My Network Lab: Juniper Networks Routing Fundamentals

Routing is the process of moving data between Layer 3 networks.

Two primary routing components:

End-to-end physical communications path.
Ensure all Layer 3 (routing) devices within the network path have the necessary routing information.

Routing Table

The Junos OS receives multiple routes for a given destination prefix, it selects a single route as the active route. It also support multiple, equal-cost routes.

Forwarding Table

The Junos OS uses the active route for each destination prefix to populate the forwarding table. The forwarding table determines the outgoing interface and Layer 2 rewrite information for each packet.

Multiple Routing Tables

The Junos OS can accommodate multiple routing tables and creates additional routing tables when the configuration requires it. The primary routing table inet.0 stores IPv4 unicast routes and inet6.0 for IPv6 unicast routes.

Preferred Routing Information Sources

The Junos OS uses route preferences (administrative distance/AD in Cisco) to differentiate routes received from different routing information sources. The lower preference values are preferred over high preference values.

Viewing the Route Table

[edit]

jadmin@JR-1# set routing-options ?

Possible completions:

> access Access routes

> access-internal Access-internal routes

> admin-groups-extended Extended administrative groups

> admin-groups-extended-range Extended administrative groups range

> aggregate Coalesced routes

+ apply-groups Groups from which to inherit configuration data

+ apply-groups-except Don't inherit configuration data from these groups

> auto-export Export routes between routing instances

> autonomous-system Autonomous system number

bgp-orf-cisco-mode Using BGP ORF capability code 130 and Prefix ORF type 128

> bmp BGP Monitoring Protocol (BMP) configuration

> confederation Confederation autonomous system number

> dynamic-tunnels Dynamic tunnel definitions

> fate-sharing Fate-sharing links or nodes database

> flow Locally defined flow routing information

> forwarding-table

> generate Route of last resort

> graceful-restart Graceful or hitless routing restart options

+ instance-export Export policy for instance RIBs

+ instance-import Import policy for instance RIBs

> interface-routes Define routing table groups for interface routes

> martians Invalid routes

> maximum-paths Maximum number of paths

> maximum-prefixes Maximum number of prefixes

med-igp-update-interval Delay (in minutes) in updating MED IGP for bgp groups

with 'delay-med-update'

> multicast Global multicast options

> options Miscellaneous options

> ppm Set periodic packet management properties

> resolution Route next-hop resolution options

> rib Routing table options

> rib-groups Group of routing tables

route-distinguisher-id Identifier used in route distinguishers for routing in

stances

route-record Enable route recording

router-id Router identifier

> source-routing Source-routing options

> srlg SRLG configuration

> static Static routes

> topologies Define routing topologies

> traceoptions Global routing protocol trace options

[edit]

jadmin@JR-1# set routing-options static ?

Possible completions:

+ apply-groups Groups from which to inherit configuration data

+ apply-groups-except Don't inherit configuration data from these groups

> defaults Global route options

rib-group Routing table group

> route Static route

[edit]

jadmin@JR-1# set routing-options static route ?

Possible completions:

[edit]

jadmin@JR-1# set routing-options static route 192.168.1.0/24 ?

Possible completions:

active Remove inactive route from forwarding table

+ apply-groups Groups from which to inherit configuration data

+ apply-groups-except Don't inherit configuration data from these groups

> as-path Autonomous system path

backup-pe-group Multicast source redundancy group

> bfd-liveness-detection Bidirectional Forwarding Detection (BFD) options

> color Color (preference) value

> color2 Color (preference) value 2

+ community BGP community identifier

discard Drop packets to destination; send no ICMP unreachables

install Install route into forwarding table

> lsp-next-hop LSP next hop

> metric Metric value

> metric2 Metric value 2

> metric3 Metric value 3

> metric4 Metric value 4

+ next-hop Next hop to destination

next-table Next hop to another table

no-install Don't install route into forwarding table

no-readvertise Don't mark route as eligible to be readvertised

no-resolve Don't allow resolution of indirectly connected next hops

no-retain Don't always keep route in forwarding table

> p2mp-lsp-next-hop Point-to-multipoint LSP next hop

passive Retain inactive route in forwarding table

> preference Preference value

> preference2 Preference value 2

> qualified-next-hop Next hop with qualifiers

readvertise Mark route as eligible to be readvertised

receive Install a receive route for the destination

reject Drop packets to destination; send ICMP unreachables

resolve Allow resolution of indirectly connected next hops

retain Always keep route in forwarding table

> static-lsp-next-hop Static LSP next hop

> tag Tag string

> tag2 Tag string 2

[edit]

jadmin@JR-1# set routing-options static route 192.168.1.0/24 next-hop ?

Possible completions:

<value> Next hop to destination

[ Open a set of values

[edit]

jadmin@JR-1# set routing-options static route 192.168.1.0/24 next-hop 10.1.1.2

[edit]

jadmin@JR-1# commit

commit complete

jadmin@JR-1> show route // VIEW ROUTING TABLE

inet.0: 3 destinations, 3 routes (3 active, 0 holddown, 0 hidden) // THE inet.0 IS USED FOR IPv4 UNICAST ROUTES

+ = Active Route, - = Last Active, * = Both

10.1.1.0/24 *[Direct/0] 00:06:01 // AN ASTERISK (*) INDICATES AN ACTIVE ROUTE.

> via em0.0

10.1.1.1/32 *[Local/0] 04:50:06

Local via em0.0

192.168.1.0/24 *[Static/5] 00:00:06 // ROUTE SOURCE/PREFERENCE

> to 10.1.1.2 via em0.0

You can filter the show route output by destination prefix, protocol type and other attributes.

jadmin@JR-1> show route 10.1.1.1/24 ?

Possible completions:

<[Enter]> Execute this command

active-path Show active paths

advertising-protocol Show information in format intended for particular routing protocol

all Show all entries, including hidden entries

aspath-regex BGP AS path regular expression for entries to match

best Show longest matching route

brief Display brief output

ccc Name of entry in MPLS table with a circuit cross-connect

interface

+ community Identifier for community (can include wildcards)

community-name Name of configured community policy to match

damping Show entries subjected to particular kind of route damping

detail Display detailed output

exact Show routes that match exactly

extensive Display extensive output

hidden Show hidden entries

inactive-path Show inactive paths

inactive-prefix Show inactive route destinations

label Label of entry in MPLS routing table

label-switched-path Name of LSP tunnel associated with entries

logical-system Name of logical system, or 'all'

match-prefix Regular expression to match formatted prefix

next-hop IP address of next hop that is destination for entries

no-community Show entries with no associated community

output Show entries sent out a particular interface

private Show private table routes

protocol Name of protocol that is source for entries

range Show all entries in prefix range

rd-prefix Route distinguisher with ip prefix (rd:prefix)

receive-protocol Show information in format received from particular routi

ng protocol

source-gateway IP address of source router for entries

static-label-switched-path Name of static LSP tunnel associated with entries

table Name of routing table

terse Display terse output

| Pipe through a command

jadmin@JR-1> show route 10.1.1.1/24 exact

inet.0: 2 destinations, 2 routes (2 active, 0 holddown, 0 hidden)

+ = Active Route, - = Last Active, * = Both

10.1.1.0/24 *[Direct/0] 00:02:24

> via em0.0

jadmin@JR-1> show route protocol ?

Possible completions:

access Access route

access-internal Access-internal route

aggregate Locally generated aggregate route

bgp Border Gateway Protocol

ccc Circuit cross-connect

direct Directly connected routes

dvmrp Distance Vector Multicast Routing Protocol

esis End System-to-Intermediate System

flow Locally defined flow route

isis Intermediate System-to-Intermediate System

l2circuit Layer 2 circuit

l2vpn Layer 2 virtual private network

ldp Label Distribution Protocol

local Local system addresses

mpls Multiprotocol Label Switching

msdp Multicast Source Discovery Protocol

mvpn BGP-MVPN Protocol

ospf Open Shortest Path First

ospf2 Open Shortest Path First Version 2

ospf3 Open Shortest Path First Version 3

pim Protocol Independent Multicast

rip Routing Information Protocol

ripng Routing Information Protocol for IPv6

rsvp Resource Reservation Protocol

rtarget Local route target VPN membership

static Statically defined prefixes

tunnel Dynamic tunnel

vpn Layer 3 virtual private network

jadmin@JR-1> show route protocol static

inet.0: 3 destinations, 3 routes (3 active, 0 holddown, 0 hidden)

+ = Active Route, - = Last Active, * = Both

192.168.1.0/24 *[Static/5] 00:03:24

> to 10.1.1.2 via em0.0

jadmin@JR-1> show route ?

Possible completions:

<[Enter]> Execute this command

<destination> IP address and optional prefix length of destination

active-path Show active paths

advertising-protocol Show information in format intended for particular routi

ng protocol

all Show all entries, including hidden entries

aspath-regex BGP AS path regular expression for entries to match

best Show longest matching route

brief Display brief output

ccc Name of entry in MPLS table with a circuit cross-connect

interface

+ community Identifier for community (can include wildcards)

community-name Name of configured community policy to match

damping Show entries subjected to particular kind of route damping

detail Display detailed output

exact Show routes that match exactly

export Show instance export information

extensive Display extensive output

flow Show flow routing information

forwarding-table Show entries in all forwarding tables

hidden Show hidden entries

inactive-path Show inactive paths

inactive-prefix Show inactive route destinations

instance Show routing instances information

label Label of entry in MPLS routing table

label-switched-path Name of LSP tunnel associated with entries

localization Show route localization information

logical-system Name of logical system, or 'all'

martians Show martian networks

match-prefix Regular expression to match formatted prefix

next-hop IP address of next hop that is destination for entries

no-community Show entries with no associated community

output Show entries sent out a particular interface

private Show private table routes

protocol Name of protocol that is source for entries

range Show all entries in prefix range

rd-prefix Route distinguisher with ip prefix (rd:prefix)

receive-protocol Show information in format received from particular routing protocol

resolution Show next-hop resolution database

rib-groups Show group of routing tables

snooping Show routes for multicast snooping

source-gateway IP address of source router for entries

static-label-switched-path Name of static LSP tunnel associated with entries

summary Show routing table statistics

table Name of routing table

terse Display terse output

| Pipe through a command

jadmin@JR-1> show route forwarding-table // VIEW FORWARDING TABLE

Routing table: default.inet

Internet:

Destination Type RtRef Next hop Type Index NhRef Netif

default perm 0 rjct 36 1 // WHEN NO PACKET MATCHING ENTRY EXIST EXCEPT FOR USER-DEFINE DEFAULT ROUTE; IT SENDS ICMP UNREACHABLE BACK TO THE SENDER

0.0.0.0/32 perm 0 dscd 34 1

10.1.1.0/24 intf 0 rslv 543 1 em0.0

10.1.1.0/32 dest 0 10.1.1.0 recv 541 1 em0.0

10.1.1.1/32 intf 0 10.1.1.1 locl 542 2

10.1.1.1/32 dest 0 10.1.1.1 locl 542 2

10.1.1.2/32 dest 0 10.1.1.2 hold 548 3 em0.0

10.1.1.10/32 dest 1 2:0:4c:4f:4f:50 ucst 547 2 em0.0

10.1.1.255/32 dest 0 10.1.1.255 bcst 540 1 em0.0

192.168.1.0/24 user 0 10.1.1.2 hold 548 3 em0.0

224.0.0.0/4 perm 0 mdsc 35 1

224.0.0.1/32 perm 0 224.0.0.1 mcst 31 1

255.255.255.255/32 perm 0 bcst 32 1

Routing table: __master.anon__.inet

Internet:

Destination Type RtRef Next hop Type Index NhRef Netif

default perm 0 rjct 517 1

0.0.0.0/32 perm 0 dscd 515 1

224.0.0.0/4 perm 0 mdsc 516 1

224.0.0.1/32 perm 0 224.0.0.1 mcst 512 1

255.255.255.255/32 perm 0 bcst 513 1

Routing table: default.iso

ISO:

Destination Type RtRef Next hop Type Index NhRef Netif

default perm 0 rjct 60 1

Routing table: __master.anon__.iso

ISO:

Destination Type RtRef Next hop Type Index NhRef Netif

default perm 0 rjct 523 1

Routing table: default.inet6

Internet6:

Destination Type RtRef Next hop Type Index NhRef Netif

default perm 0 rjct 44 1

::/128 perm 0 dscd 42 1

ff00::/8 perm 0 mdsc 43 1

ff02::1/128 perm 0 ff02::1 mcst 39 1

Routing table: __master.anon__.inet6

Internet6:

Destination Type RtRef Next hop Type Index NhRef Netif

default perm 0 rjct 532 1

::/128 perm 0 dscd 530 1

ff00::/8 perm 0 mdsc 531 1

ff02::1/128 perm 0 ff02::1 mcst 528 1

Routing table: default.mpls

MPLS:

Destination Type RtRef Next hop Type Index NhRef Netif

default perm 0 dscd 50 1

Routing table: :mpls-oam.mpls

MPLS:

Destination Type RtRef Next hop Type Index NhRef Netif

default perm 0 dscd 525 1

Routing table: default-switch.bridge

VPLS:

Destination Type RtRef Next hop Type Index NhRef Netif

default perm 0 dscd 536 1

Master Routing Instance (Global Routing in Cisco)

jadmin@JR-1> show route instance // DEFAULT UNICAST ROUTING "MASTER" INSTANCE

Instance Type

Primary RIB Active/holddown/hidden

master forwarding

inet.0 3/0/0

__juniper_private1__ forwarding // PRIVATE ROUTING INSTANCE USED FOR INTERNAL COMMUNICATIONS BETWEEN HARDWARE COMPONENTS (JUST IGNORE)

__juniper_private1__.inet.0 1/0/0

__juniper_private1__.inet6.0 1/0/0

__juniper_private2__ forwarding

__juniper_private2__.inet.0 0/0/1

__master.anon__ forwarding

User-Defined Routing Instance (Virtual Routing and Forwarding or VRF in Cisco)

jadmin@JR-1> configure

Entering configuration mode

Users currently editing the configuration:

jadmin terminal p2 (pid 2116) on since 2020-10-20 21:56:23 SGT, idle 01:50:11

[edit]

The configuration has been changed but not committed

[edit]

jadmin@JR-1# edit routing-instances ?

Possible completions:

<[Enter]> Execute this command

<instance_name> Routing instance name

| Pipe through a command

[edit]

jadmin@JR-1# edit routing-instances CUST-A

[edit routing-instances CUST-A]

jadmin@JR-1# set ?

Possible completions:

> access Network access configuration

> access-profile Access profile for this instance

+ apply-groups Groups from which to inherit configuration data

+ apply-groups-except Don't inherit configuration data from these groups

description Text description of routing instance

> forwarding-options Forwarding options configuration

instance-role Primary role of L2Backhaul-vpn router

instance-type Type of routing instance

> interface Interface name for this routing instance

> l2vpn-id Layer-2 vpn-id for this instance

no-vrf-advertise Don't advertise this instance to remote PEs

no-vrf-propagate-ttl Disable TTL propagation from IP to MPLS (on push) and MP

LS to IP (on pop)

> protocols Routing protocol configuration

> provider-tunnel Provider tunnel configuration

> route-distinguisher Route distinguisher for this instance

> routing-options Protocol-independent routing option configuration

> services Service PIC daemon configuration

> system System parameters

vlan-model Subscriber vlan-model in L2Wholesale framework

> vrf-advertise-selective Override no-vrf-advertise knob for the specified addr

ess family

+ vrf-export Export policy for VRF instance RIBs

+ vrf-import Import policy for VRF instance RIBs

vrf-propagate-ttl Enable TTL propagation from IP to MPLS (on push) and MPLS

to IP (on pop)

> vrf-table-label Advertise a single VPN label for all routes in the VRF

> vrf-target VRF target community configuration

[edit routing-instances CUST-A]

jadmin@JR-1# set instance-type ?

Possible completions:

forwarding Forwarding instance

l2vpn Layer 2 VPN routing instance

mpls-internet-multicast Internet Multicast over MPLS routing instance

no-forwarding Nonforwarding instance

virtual-router Virtual routing instance

vpls VPLS routing instance

vrf Virtual routing forwarding instance

[edit routing-instances CUST-A]

jadmin@JR-1# set instance-type virtual-router

[edit routing-instances CUST-A]

jadmin@JR-1# set interface lo0.10

[edit routing-instances CUST-A]

jadmin@JR-1# set routing-options static route 0.0.0.0/0 next-hop 172.16.1.1

[edit routing-instances CUST-A]

jadmin@JR-1# show

instance-type virtual-router;

interface lo0.10; ## 'lo0.10' is not defined

routing-options {

static {

route 0.0.0.0/0 next-hop 172.16.1.1;

}

[edit routing-instances CUST-A]

jadmin@JR-1# commit

commit complete

Static Routes

Static routing is ideal in small networks or where absolute control of routing is necessary. All static routes are configured in the edit routing-options hierarchy. By default, the next-hop IP address of the static routes configured must be reachable using a direct route since Junos OS doesn't perform a recursive lookup of next hops by default.

Next-hop value can be a bit bucket, which is analogous to dropping the packet. You can use keywords reject (the system sends an ICMP unreachable back to the source) or discard (drops the packet silently).

jadmin@JR-1> configure

Entering configuration mode

[edit]

jadmin@JR-1# edit routing-options

[edit routing-options]

jadmin@JR-1# show

static {

route 192.168.1.0/24 next-hop 10.1.1.2;

}

[edit routing-options]

jadmin@JR-1# set static route 192.168.2.0/24 next-hop 10.1.1.3 ?

Possible completions:

<[Enter]> Execute this command

active Remove inactive route from forwarding table

+ apply-groups Groups from which to inherit configuration data

+ apply-groups-except Don't inherit configuration data from these groups

> as-path Autonomous system path

backup-pe-group Multicast source redundancy group

> bfd-liveness-detection Bidirectional Forwarding Detection (BFD) options

> color Color (preference) value

> color2 Color (preference) value 2

+ community BGP community identifier

install Install route into forwarding table

> lsp-next-hop LSP next hop

> metric Metric value

> metric2 Metric value 2

> metric3 Metric value 3

> metric4 Metric value 4

+ next-hop Next hop to destination

no-install Don't install route into forwarding table

no-readvertise Don't mark route as eligible to be readvertised

no-resolve Don't allow resolution of indirectly connected next hops

no-retain Don't always keep route in forwarding table

> p2mp-lsp-next-hop Point-to-multipoint LSP next hop

passive Retain inactive route in forwarding table

> preference Preference value

> preference2 Preference value 2

> qualified-next-hop Next hop with qualifiers

readvertise Mark route as eligible to be readvertised

resolve Allow resolution of indirectly connected next hops

retain Always keep route in forwarding table

> static-lsp-next-hop Static LSP next hop

> tag Tag string

> tag2 Tag string 2

| Pipe through a command

[edit routing-options]

jadmin@JR-1# set static route 192.168.2.0/24 next-hop 10.1.1.3 no-readvertise

[edit routing-options]

jadmin@JR-1# set rib ?

Possible completions:

<rib_name> Routing table name

[edit routing-options]

jadmin@JR-1# set rib inet6.0 ?

Possible completions:

> access Access routes

> access-internal Access-internal routes

> aggregate Coalesced routes

+ apply-groups Groups from which to inherit configuration data

+ apply-groups-except Don't inherit configuration data from these groups

> generate Route of last resort

> martians Invalid routes

> maximum-paths Maximum number of paths

> maximum-prefixes Maximum number of prefixes

> static Static routes

[edit routing-options]

jadmin@JR-1# set rib inet6.0 static ?

Possible completions:

+ apply-groups Groups from which to inherit configuration data

+ apply-groups-except Don't inherit configuration data from these groups

> defaults Global route options

rib-group Routing table group

> route Static route

[edit routing-options]

jadmin@JR-1# set rib inet6.0 static route ?

Possible completions:

[edit routing-options]

jadmin@JR-1# set rib inet6.0 static route 0::/0 ?

Possible completions:

active Remove inactive route from forwarding table

+ apply-groups Groups from which to inherit configuration data

+ apply-groups-except Don't inherit configuration data from these groups

> as-path Autonomous system path

backup-pe-group Multicast source redundancy group

> bfd-liveness-detection Bidirectional Forwarding Detection (BFD) options

> color Color (preference) value

> color2 Color (preference) value 2

+ community BGP community identifier

discard Drop packets to destination; send no ICMP unreachables

install Install route into forwarding table

> lsp-next-hop LSP next hop

> metric Metric value

> metric2 Metric value 2

> metric3 Metric value 3

> metric4 Metric value 4

+ next-hop Next hop to destination

next-table Next hop to another table

no-install Don't install route into forwarding table

no-readvertise Don't mark route as eligible to be readvertised

no-resolve Don't allow resolution of indirectly connected next ho

no-retain Don't always keep route in forwarding table

> p2mp-lsp-next-hop Point-to-multipoint LSP next hop

passive Retain inactive route in forwarding table

> preference Preference value

> preference2 Preference value 2

> qualified-next-hop Next hop with qualifiers

readvertise Mark route as eligible to be readvertised

receive Install a receive route for the destination

reject Drop packets to destination; send ICMP unreachables

resolve Allow resolution of indirectly connected next hops

retain Always keep route in forwarding table

> static-lsp-next-hop Static LSP next hop

> tag Tag string

> tag2 Tag string 2

[edit routing-options]

jadmin@JR-1# set rib inet6.0 static route 0::/0 next-hop ?

Possible completions:

<value> Next hop to destination

[ Open a set of values

[edit routing-options]

jadmin@JR-1# set rib inet6.0 static route 0::/0 next-hop 2001::1

jadmin@JR-1# show

rib inet6.0 {

static {

route 0::/0 next-hop 2001::1; // IPv6 DEFAULT STATIC ROUTE

}

static {

route 192.168.1.0/24 next-hop 10.1.1.2;

route 192.168.2.0/24 {

next-hop 10.1.1.3;

no-readvertise; // RESTRICT A ROUTE FROM BEING ADVERTISED INTO A DYNAMIC ROUTING PROTOCOL THROUGH ROUTING POLICY; RECOMMENDED FOR STATIC ROUTES USED FOR MANAGEMENT TRAFFIC

}

[edit routing-options]

jadmin@JR-1# commit

commit complete

[edit routing-options]

jadmin@JR-1# run show route protocol ?

Possible completions:

access Access route

access-internal Access-internal route

aggregate Locally generated aggregate route

bgp Border Gateway Protocol

ccc Circuit cross-connect

direct Directly connected routes

dvmrp Distance Vector Multicast Routing Protocol

esis End System-to-Intermediate System

flow Locally defined flow route

isis Intermediate System-to-Intermediate System

l2circuit Layer 2 circuit

l2vpn Layer 2 virtual private network

ldp Label Distribution Protocol

local Local system addresses

mpls Multiprotocol Label Switching

msdp Multicast Source Discovery Protocol

mvpn BGP-MVPN Protocol

ospf Open Shortest Path First

ospf2 Open Shortest Path First Version 2

ospf3 Open Shortest Path First Version 3

pim Protocol Independent Multicast

rip Routing Information Protocol

ripng Routing Information Protocol for IPv6

rsvp Resource Reservation Protocol

rtarget Local route target VPN membership

static Statically defined prefixes

tunnel Dynamic tunnel

vpn Layer 3 virtual private network

[edit routing-options]

jadmin@JR-1# run show route protocol static // DISPLAY STATIC ROUTES

inet.0: 4 destinations, 4 routes (4 active, 0 holddown, 0 hidden)

+ = Active Route, - = Last Active, * = Both

192.168.1.0/24 *[Static/5] 00:09:31

> to 10.1.1.2 via em0.0

192.168.2.0/24 *[Static/5] 00:00:10

> to 10.1.1.3 via em0.0

[edit routing-options]

Indirect Next Hop

By default, Junos OS requires the next-hop IP address of static routes to be reachable using a direct route since it doesn't perform a recursive lookups. You can use the resolve option to alter this behavior. It's recommended to use a dynamic routing protocol instead of a static route to resolve indirect next hops.

jadmin@JR-1> edit // ALTERNATE TO configure

Entering configuration mode

Users currently editing the configuration:

jadmin terminal p0 (pid 3731) on since 2020-10-21 00:45:43 SGT, idle 00:08:09

[edit routing-options]

[edit]

jadmin@JR-1# edit routing-options

[edit routing-options]

jadmin@JR-1# set static route 192.168.3.0/24 next-hop 10.1.1.3 ?

Possible completions:

<[Enter]> Execute this command

active Remove inactive route from forwarding table

+ apply-groups Groups from which to inherit configuration data

+ apply-groups-except Don't inherit configuration data from these groups

> as-path Autonomous system path

backup-pe-group Multicast source redundancy group

> bfd-liveness-detection Bidirectional Forwarding Detection (BFD) options

> color Color (preference) value

> color2 Color (preference) value 2

+ community BGP community identifier

install Install route into forwarding table

> lsp-next-hop LSP next hop

> metric Metric value

> metric2 Metric value 2

> metric3 Metric value 3

> metric4 Metric value 4

+ next-hop Next hop to destination

no-install Don't install route into forwarding table

no-readvertise Don't mark route as eligible to be readvertised

no-resolve Don't allow resolution of indirectly connected next hops

no-retain Don't always keep route in forwarding table

> p2mp-lsp-next-hop Point-to-multipoint LSP next hop

passive Retain inactive route in forwarding table

> preference Preference value

> preference2 Preference value 2

> qualified-next-hop Next hop with qualifiers

readvertise Mark route as eligible to be readvertised

resolve Allow resolution of indirectly connected next hops

retain Always keep route in forwarding table

> static-lsp-next-hop Static LSP next hop

> tag Tag string

> tag2 Tag string 2

| Pipe through a command

[edit routing-options]

jadmin@JR-1# set static route 192.168.3.0/24 next-hop 10.1.1.3 resolve

[edit routing-options]

jadmin@JR-1# show

rib inet6.0 {

static {

route 0::/0 next-hop 2001::1;

}

static {

route 192.168.1.0/24 next-hop 10.1.1.2;

route 192.168.2.0/24 {

next-hop 10.1.1.3;

no-readvertise;

}

route 192.168.3.0/24 {

next-hop 10.1.1.3;

resolve;

}

[edit routing-options]

Qualified Next Hop (Floating Static Route)

The qualified-next-hop option allows independent preferences for static routes towards the same destination network.

jadmin@JR-1> configure

Entering configuration mode

Users currently editing the configuration:

jadmin terminal p0 (pid 3731) on since 2020-10-21 00:45:43 SGT, idle 00:19:00

[edit routing-options]

[edit]

jadmin@JR-1# edit routing-options

[edit routing-options]

jadmin@JR-1# set static route 0.0.0.0/0 next-hop 192.168.10.1 ?

Possible completions:

<[Enter]> Execute this command

active Remove inactive route from forwarding table

+ apply-groups Groups from which to inherit configuration data

+ apply-groups-except Don't inherit configuration data from these groups

> as-path Autonomous system path

backup-pe-group Multicast source redundancy group

> bfd-liveness-detection Bidirectional Forwarding Detection (BFD) options

> color Color (preference) value

> color2 Color (preference) value 2

+ community BGP community identifier

install Install route into forwarding table

> lsp-next-hop LSP next hop

> metric Metric value

> metric2 Metric value 2

> metric3 Metric value 3

> metric4 Metric value 4

+ next-hop Next hop to destination

no-install Don't install route into forwarding table

no-readvertise Don't mark route as eligible to be readvertised

no-resolve Don't allow resolution of indirectly connected next hops

no-retain Don't always keep route in forwarding table

> p2mp-lsp-next-hop Point-to-multipoint LSP next hop

passive Retain inactive route in forwarding table

> preference Preference value

> preference2 Preference value 2

> qualified-next-hop Next hop with qualifiers

readvertise Mark route as eligible to be readvertised

resolve Allow resolution of indirectly connected next hops

retain Always keep route in forwarding table

> static-lsp-next-hop Static LSP next hop

> tag Tag string

> tag2 Tag string 2

| Pipe through a command

[edit routing-options]

jadmin@JR-1# set static route 0.0.0.0/0 next-hop 192.168.10.1 qualified-next-hop ?

Possible completions:

<nexthop> Next hop to destination

[edit routing-options]

jadmin@JR-1# set static route 0.0.0.0/0 next-hop 192.168.10.1 qualified-next-hop 192.168.10.254

jadmin@JR-1# set static route 0.0.0.0/0 next-hop 192.168.10.1 qualified-next-hop 192.168.10.254 ?

Possible completions:

<[Enter]> Execute this command

+ apply-groups Groups from which to inherit configuration data

+ apply-groups-except Don't inherit configuration data from these group

> bfd-liveness-detection Bidirectional Forwarding Detection (BFD) optio

interface Interface of qualified next hop

mac-address Next-hop Mac Address

metric Metric of qualified next hop

preference Preference of qualified next hop

| Pipe through a command

[edit routing-options]

jadmin@JR-1# set static route 0.0.0.0/0 next-hop 192.168.10.1 qualified-next-hop 192.168.10.254 preference ?

Possible completions:

<preference> Preference of qualified next hop

[edit routing-options]

jadmin@JR-1# set static route 0.0.0.0/0 next-hop 192.168.10.1 qualified-next-hop 192.168.10.254 preference 7

[edit routing-options]

jadmin@JR-1# show

rib inet6.0 {

static {

route 0::/0 next-hop 2001::1;

}

static {

route 192.168.1.0/24 next-hop 10.1.1.2;

route 192.168.2.0/24 {

next-hop 10.1.1.3;

no-readvertise;

}

route 192.168.3.0/24 {

next-hop 10.1.1.3;

resolve;

}

route 0.0.0.0/0 {

next-hop 192.168.10.1; // PRIMARY NEXT HOP WITH DEFAULT PREFERENCE 5

qualified-next-hop 192.168.10.254 { // SECONDARY NEXT HOP WITH USER DEFINED PREFERENCE 7; FLOATING STATIC ROUTE IN CISCO

preference 7;

}

Dynamic Routing

You simply configure the network interfaces to participate in a dynamic routing protocol. Devices running the same routing protocol can dynamically learn routing information from each other.

The benefits of dynamic routing include:

Lower administrative overhead - the device learns routing information automatically, which eliminates the need for manual route definition.
Increased network availability - during a network failure, dynamic routing can reroute traffic automatically
Greater network scalability - the device easily manage network growth by dynamically learning routes

I modified my Juniper virtual by directly connecting two Juniper VM routers.

To view the network adapter in VirtualBox, go to Tools > Network.

By default, there's only a single VirtualBox Host-Only Ethernet Adapter. You can add network adapters for the VM as needed.

In my Junos virtual lab, I just needed one VirtualBox Ethernet adapter to connect between two Junos Olive VM.

Under DHCP Server > deselect Enable.

To add the Junos VM in VirtualBox, go to File > Import Appliance.

Locate the Juniper Olive VM OVA file > click Next.

Deselect DVD and Sound Card > review VM settings > click Import.

Select the Junos VM > click Settings.

Go to Network > Adapter 1 tab > select: Enable Network Adapter > select Attached to: Bridged Adapter.

Select Name: Microsoft Loopback Adapter > click OK.

This will be the connection between my Windows machine and Junos VM for local management access (Telnet/SSH).

Leave the default settings under the Advanced section.

Go to Adapter 2 tab > select: Enable Network Adapter > select Attached to: Host-only Adapter > select Name: VirtualBox Host-Only Ethernet Adapter > click OK.

Leave the default settings under the Advanced section.

Rename the Junos VM under General > Basic tab > Name: JR1 > click OK.

Create another Junos Olive VM using the same steps above except there's only a Host-Only Network Adapter.

You can either manually import the VM again or clone by doing a right-click on JR1 VM > select Clone.

The JR1 VM will have interfaces em0 (Adapter 1) and em1 (Adapter 2), respectively.

Interface em0 will be the configured to connect my Windows machine and em1 for the link to JR2.

Below are the base configuration commands in JR1.

configure

set system host-name JR1

set system root-authentication plain-text-password

juniper123

set system services telnet

set system services ssh root-login allow

set system login message "Juniper VM Lab - JR1 "

set interfaces em0 unit 0 family inet address 10.1.1.1/24

set interfaces em1 unit 0 family inet address 172.25.1.1/30

set interfaces lo0 unit 0 family inet address 172.20.1.1/32

edit system login

set user jadmin class super-user

set user jadmin authentication plain-text-password

jadmin123

commit

jadmin@JR1> request system configuration rescue save // SAVE A BASELINE CONFIG IN CASE OF A ROLLBACK

jadmin@JR1> show configuration

## Last commit: 2020-10-25 10:35:53 UTC by jadmin

version 12.1R1.9;

system {

host-name JR1;

root-authentication {

encrypted-password "$1$z1.L2Pfo$sR97/UUK7PPZX2RA2Fumz1"; ## SECRET-DATA

}

message "Juniper VM Lab - JR1";

user jadmin {

uid 2000;

class super-user;

authentication {

encrypted-password "$1$A42xsAPa$JTE2sbr19Nw1D6.QzhoWF."; ## SEC

ET-DATA

}

services {

ssh {

root-login allow;

}

telnet;

}

syslog {

user * {

any emergency;

}

file messages {

any notice;

authorization info;

}

file interactive-commands {

interactive-commands any;

}

interfaces {

em0 {

unit 0 {

family inet {

address 10.1.1.1/24;

}

em1 {

unit 0 {

family inet {

address 172.25.1.1/30; // LAYER 3 LINK TO JR2

}

lo0 {

unit 0 {

family inet {

address 172.20.1.1/32;

}

Below are the base configuration on JR2. Notice there's only em0 interface (Adapter 1).

jadmin@JR1> telnet 172.25.1.2

Trying 172.25.1.2...

Connected to 172.25.1.2.

Escape character is '^]'.

Juniper VM Lab - JR2

JR2 (ttyp0)

Password:

--- JUNOS 12.1R1.9 built 2012-03-24 12:52:33 UTC

jadmin@JR2> show configuration

## Last commit: 2020-10-25 10:44:03 UTC by root

version 12.1R1.9;

system {

host-name JR2;

root-authentication {

encrypted-password "$1$rP2JRJrT$OduXdfKa5/ZvMyrI44PiI."; ## SECRET-DATA

}

message "Juniper VM Lab - JR2";

user jadmin {

uid 2000;

class super-user;

authentication {

encrypted-password "$1$Z7dp.tdz$1p0033n2IiAt9nCYId1HM0"; ## SECR

ET-DATA

}

services {

ssh {

root-login allow;

}

telnet;

}

syslog {

user * {

any emergency;

}

file messages {

any notice;

authorization info;

}

file interactive-commands {

interactive-commands any;

}

interfaces {

em0 {

unit 0 {

family inet {

address 172.25.1.2/30; // LAYER 3 LINK TO JR1

}

lo0 {

unit 0 {

family inet {

address 172.20.2.1/32;

}

jadmin@JR2> ping 172.25.1.1 count 10 rapid

PING 172.25.1.1 (172.25.1.1): 56 data bytes

!!!!!!!!!!

--- 172.25.1.1 ping statistics ---

10 packets transmitted, 10 packets received, 0% packet loss

round-trip min/avg/max/stddev = 0.451/0.839/1.591/0.348 ms

jadmin@JR2> request system configuration rescue save

Case Study: Configuring OSPF

jadmin@JR1> configure

Entering configuration mode

Users currently editing the configuration:

root terminal v0 (pid 1488) on since 2020-10-25 10:26:47 UTC, idle 00:29:19

[edit system login]

[edit]

jadmin@JR1# edit protocols ?

Possible completions:

<[Enter]> Execute this command

> ancp Access Node Control Protocol options

> bfd Bidirectional Forwarding Detection (BFD) options

> bgp BGP options

> connections Circuit cross-connect configuration

> dot1x 802.1X options

> dvmrp DVMRP options

> igmp IGMP options

> ilmi Interim Local Management Interface Protocol configuration

> isis IS-IS options

> l2circuit Configuration for Layer 2 circuits over MPLS

> l2iw Configuration for Layer 2 interworking

> lacp Link Aggregation Control Protocol configuration

> ldp LDP options

> link-management LMP options

> lldp Link Layer Detection Protocol

> mld MLD options

> mpls Multiprotocol Label Switching options

> msdp MSDP configuration

> mvrp MVRP configuration

> oam Operation, Administration, and Management configuration

> ospf OSPF configuration

> ospf3 OSPFv3 configuration

> pgm PGM options

> pim PIM configuration

> ppp Configure PPP process

> ppp-service Configure PPP service

> pppoe Configure PPPoE process

> rip RIP options

> ripng RIPng options

> router-advertisement IPv6 router advertisement options

> router-discovery ICMP router discovery options

> rsvp RSVP options

> sap Session Advertisement Protocol options

> vrrp VRRP options

| Pipe through a command

[edit]

jadmin@JR1# edit protocols ospf

[edit protocols ospf]

jadmin@JR1# set area ?

Possible completions:

<area_id> Area ID

[edit protocols ospf]

jadmin@JR1# set area 0 interface em0.0 ?

Possible completions:

<[Enter]> Execute this command

+ apply-groups Groups from which to inherit configuration data

+ apply-groups-except Don't inherit configuration data from these groups

> authentication

> bandwidth-based-metrics Configure bandwidth based metrics

> bfd-liveness-detection Bidirectional Forwarding Detection options

dead-interval Dead interval (seconds) (1..65535)

demand-circuit Interface functions as a demand circuit

disable Disable OSPF on this interface

dynamic-neighbors Learn neighbors dynamically on a p2mp interface

flood-reduction Enable flood reduction

hello-interval Hello interval (seconds) (1..255)

interface-type Type of interface

ipsec-sa IPSec security association name

> ldp-synchronization Advertise maximum metric until LDP is operational

link-protection Protect interface from link faults only

metric Interface metric (1..65535)

> neighbor NBMA neighbor

no-eligible-backup Not eligible to backup traffic from protected interfaces

no-interface-state-traps Do not send interface state change traps

no-neighbor-down-notification Don't inform other protocols about neighbor dow

n events

node-link-protection Protect interface from both link and node faults

> passive Do not run OSPF, but advertise it

poll-interval Poll interval for NBMA interfaces (1..65535)

priority Designated router priority (0..255)

retransmit-interval Retransmission interval (seconds) (1..65535)

secondary Treat interface as secondary

te-metric Traffic engineering metric (1..4294967295)

> topology Topology specific attributes

transit-delay Transit delay (seconds) (1..65535)

| Pipe through a command

[edit protocols ospf]

jadmin@JR1# set area 0 interface em0.0 passive // THE passive OPTION PROHIBITS FORMING OSPF NEIGHBOR ADJACENCY SINCE IT'S A LAN SUBNET AND NOT ANOTHER JUNIPER DEVICE

[edit protocols ospf]

jadmin@JR1# set area 0 interface em1.0

[edit protocols ospf]

jadmin@JR1# set area 0 interface lo0.0

[edit protocols ospf]

jadmin@JR1# show

area 0.0.0.0 {

interface em0.0 {

passive;

}

interface em1.0;

interface lo0.0;

}

[edit protocols ospf]

jadmin@JR1# commit and-quit

commit complete

Exiting configuration mode

jadmin@JR1> show ospf ?

Possible completions:

backup Show OSPF backup information

context-identifier Show OSPF context identifier information

database Show OSPF link-state database

interface Show OSPF interface status information

io-statistics Show OSPF I/O statistics

log Show shortest-path-first calculations from OSPF log

neighbor Show OSPF neighbor status information

overview Show overview of OSPF information

route Show OSPF routing table

statistics Show OSPF statistics

jadmin@JR1> show ospf neighbor

Address Interface State ID Pri Dead

172.25.1.2 em1.0 Full 172.20.2.1 128 31 // FULL MEANS OSPF NEIGHBORS CAN EXCHANGE ROUTING INFO

jadmin@JR1> show ospf database

OSPF database, Area 0.0.0.0

Type ID Adv Rtr Seq Age Opt Cksum Len

Router *172.20.1.1 172.20.1.1 0x80000004 103 0x22 0x79b1 60

Router 172.20.2.1 172.20.2.1 0x80000004 99 0x22 0xb192 48

Network *172.25.1.1 172.20.1.1 0x80000001 103 0x22 0xb774 32

jadmin@JR1> show ospf interface

Interface State Area DR ID BDR ID Nbrs

em0.0 DRother 0.0.0.0 0.0.0.0 0.0.0.0 0

em1.0 DR 0.0.0.0 172.20.1.1 172.20.2.1 1

lo0.0 DR 0.0.0.0 172.20.1.1 0.0.0.0 0

jadmin@JR1> show ospf io-statistics

Packets read: 9, average per run: 1.00, max run: 0

Receive errors:

None

jadmin@JR1> show ospf log

Topology default SPF log:

Last instance of each event type

When Type Elapsed

00:02:36 SPF 0.000133

00:02:36 Stub 0.000062

00:02:36 Interarea 0.000116

00:02:36 External 0.000003

00:02:36 NSSA 0.000003

00:02:36 Cleanup 0.003071

Maximum length of each event type

When Type Elapsed

00:02:43 SPF 0.002320

00:07:42 Stub 0.001925

00:02:36 Interarea 0.000116

00:02:43 External 0.000003

00:07:47 NSSA 0.000009

00:02:36 Cleanup 0.003071

Last 100 events

When Type Elapsed

00:07:47 SPF 0.000019

00:07:47 Stub 0.000011

00:07:47 Interarea 0.000001

00:07:47 External 0.000001

00:07:47 NSSA 0.000009

00:07:47 Cleanup 0.000923

00:07:47 Total 0.001435

00:07:42 SPF 0.000016

00:07:42 Stub 0.001925

00:07:42 Interarea 0.000003

00:07:42 External 0.000002

00:07:42 NSSA 0.000002

00:07:42 Cleanup 0.000029

00:07:42 Total 0.001998

00:02:43 SPF 0.002320

00:02:43 Stub 0.000015

00:02:43 Interarea 0.000003

00:02:43 External 0.000003

00:02:43 NSSA 0.000002

00:02:43 Cleanup 0.000028

00:02:43 Total 0.002451

00:02:36 SPF 0.000133

00:02:36 Stub 0.000062

00:02:36 Interarea 0.000116

00:02:36 External 0.000003

00:02:36 NSSA 0.000003

00:02:36 Cleanup 0.003071

00:02:36 Total 0.003569

jadmin@JR1> show ospf overview

Instance: master

Router ID: 172.20.1.1

Route table index: 0

LSA refresh time: 50 minutes

Area: 0.0.0.0

Stub type: Not Stub

Authentication Type: None

Area border routers: 0, AS boundary routers: 0

Neighbors

Up (in full state): 1

Topology: default (ID 0)

Prefix export count: 0

Full SPF runs: 4

SPF delay: 0.200000 sec, SPF holddown: 5 sec, SPF rapid runs: 3

Backup SPF: Not Needed

jadmin@JR1> show ospf route

Topology default Route Table:

Prefix Path Route NH Metric NextHop Nexthop

Type Type Type Interface Address/LSP

172.20.2.1 Intra Router IP 1 em1.0 172.25.1.2

10.1.1.0/24 Intra Network IP 1 em0.0

172.20.1.1/32 Intra Network IP 0 lo0.0

172.20.2.1/32 Intra Network IP 1 em1.0 172.25.1.2

172.25.1.0/30 Intra Network IP 1 em1.0

jadmin@JR1> show ospf statistics

Packet type Total Last 5 seconds

Sent Received Sent Received

Hello 72 29 1 0

DbD 3 2 0 0

LSReq 1 1 0 0

LSUpdate 2 2 0 0

LSAck 2 1 0 0

DBDs retransmitted : 0, last 5 seconds : 0

LSAs flooded : 0, last 5 seconds : 0

LSAs flooded high-prio : 2, last 5 seconds : 0

LSAs retransmitted : 0, last 5 seconds : 0

LSAs transmitted to nbr: 1, last 5 seconds : 0

LSAs requested : 1, last 5 seconds : 0

LSAs acknowledged : 2, last 5 seconds : 0

Flood queue depth : 0

Total rexmit entries : 0

db summaries : 0

lsreq entries : 0

Receive errors:

None

jadmin@JR1> show route protocol ?

Possible completions:

access Access route

access-internal Access-internal route

aggregate Locally generated aggregate route

bgp Border Gateway Protocol

ccc Circuit cross-connect

direct Directly connected routes

dvmrp Distance Vector Multicast Routing Protocol

esis End System-to-Intermediate System

flow Locally defined flow route

isis Intermediate System-to-Intermediate System

l2circuit Layer 2 circuit

l2vpn Layer 2 virtual private network

ldp Label Distribution Protocol

local Local system addresses

mpls Multiprotocol Label Switching

msdp Multicast Source Discovery Protocol

mvpn BGP-MVPN Protocol

ospf Open Shortest Path First

ospf2 Open Shortest Path First Version 2

ospf3 Open Shortest Path First Version 3

pim Protocol Independent Multicast

rip Routing Information Protocol

ripng Routing Information Protocol for IPv6

rsvp Resource Reservation Protocol

rtarget Local route target VPN membership

static Statically defined prefixes

tunnel Dynamic tunnel

vpn Layer 3 virtual private network

jadmin@JR1> show route protocol ospf

inet.0: 7 destinations, 7 routes (7 active, 0 holddown, 0 hidden)

+ = Active Route, - = Last Active, * = Both

172.20.2.1/32 *[OSPF/10] 00:04:12, metric 1

> to 172.25.1.2 via em1.0

224.0.0.5/32 *[OSPF/10] 00:09:23, metric 1

MultiRecv

jadmin@JR2> configure

Entering configuration mode

Users currently editing the configuration:

root terminal v0 (pid 1482) on since 2020-10-25 10:39:29 UTC, idle 00:19:03

[edit system login]

[edit]

jadmin@JR2# edit protocols ospf

[edit protocols ospf]

jadmin@JR2# set area 0 interface em0.0

[edit protocols ospf]

jadmin@JR2# set area 0 interface lo0.0

[edit protocols ospf]

jadmin@JR2# show

area 0.0.0.0 {

interface em0.0;

interface lo0.0;

}

[edit protocols ospf]

jadmin@JR2# commit and-quit

Exiting configuration mode

jadmin@JR2> show ospf neighbor

Address Interface State ID Pri Dead

172.25.1.1 em0.0 Full 172.20.1.1 128 39

jadmin@JR2> show route protocol ospf

inet.0: 6 destinations, 6 routes (6 active, 0 holddown, 0 hidden)

+ = Active Route, - = Last Active, * = Both

10.1.1.0/24 *[OSPF/10] 00:07:07, metric 2

> to 172.25.1.1 via em0.0

172.20.1.1/32 *[OSPF/10] 00:07:07, metric 1

> to 172.25.1.1 via em0.0

224.0.0.5/32 *[OSPF/10] 00:11:25, metric 1

MultiRecv

jadmin@JR1# show | display set

set version 12.1R1.9

set system host-name JR1

set system root-authentication encrypted-password "$1$z1.L2Pfo$sR97/UUK7PPZX2RA2

Fumz1"

set system login message "Juniper VM Lab - JR1"

set system login user jadmin uid 2000

set system login user jadmin class super-user

set system login user jadmin authentication encrypted-password "$1$A42xsAPa$JTE2

sbr19Nw1D6.QzhoWF."

set system services ssh root-login allow

set system services telnet

set system syslog user * any emergency

set system syslog file messages any notice

set system syslog file messages authorization info

set system syslog file interactive-commands interactive-commands any

set interfaces em0 unit 0 family inet address 10.1.1.1/24

set interfaces em1 unit 0 family inet address 172.25.1.1/30

set interfaces lo0 unit 0 family inet address 172.20.1.1/32

set routing-options static route 0.0.0.0/0 next-hop 10.1.1.10

set protocols ospf export default-route-ospf

set protocols ospf area 0.0.0.0 interface em0.0 passive

set protocols ospf area 0.0.0.0 interface em1.0

set protocols ospf area 0.0.0.0 interface lo0.0

jadmin@JR2# show | display set

set version 12.1R1.9

set system host-name JR2

set system root-authentication encrypted-password "$1$rP2JRJrT$OduXdfKa5/ZvMyrI4

4PiI."

set system login message "Juniper VM Lab - JR2"

set system login user jadmin uid 2000

set system login user jadmin class super-user

set system login user jadmin authentication encrypted-password "$1$Z7dp.tdz$1p00

33n2IiAt9nCYId1HM0"

set system services ssh root-login allow

set system services telnet

set system syslog user * any emergency

set system syslog file messages any notice

set system syslog file messages authorization info

set system syslog file interactive-commands interactive-commands any

set interfaces em0 unit 0 family inet address 172.25.1.2/30

set interfaces lo0 unit 0 family inet address 172.20.2.1/32

set protocols ospf area 0.0.0.0 interface lo0.0

set protocols ospf area 0.0.0.0 interface em0.0

Below are the configuration commands in JR1 and JR2, respectively.

JR1

edit protocols ospf

set area 0 interface em0.0 passive

set area 0 interface em1.0

set area 0 interface lo0.0

show

commit and-quit

show ospf neighbor

show route protocol ospf

JR2

edit protocols ospf

set area 0 interface em0.0

set area 0 interface lo0.0

show

commit and-quit

show ospf neighbor

show route protocol ospf

My Network Lab

Thursday, April 1, 2021

Juniper Networks Routing Fundamentals

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