Cisco 1100 Router Flex Ports

The Cisco 1100 has a a built-in 8-port Layer 2 switch and the last two ports can be converted into a Layer 3 port. This feature is called Flex ports. The default IOS-XE that came with my Cisco 1100 router was version 17.12.x, so it supports this feature.

Restrictions for Flex Support on Layer 2 and Layer 3 Ports

• Flex port support is enabled only on Cisco 1000 Series ISRs that have four or eight front-panel switch ports.
• The last two ports of the front-panel fixed ports are the flex ports.
• The two internal VLANs are dynamically reserved for two Layer 3 ports to isolate the Layer 3 traffic and separate the forwarding database for MAC filtering.
• Flex Layer 2 and Layer 3 interfaces do not have PoE support because PoE is enabled only on the half lower number interfaces.
• Weighted Round Robin (WRR) bandwidth and Quality of Service (QoS) mapping configuration are global.
• 802.3x TX pause is not supported on flex Layer 2 and Layer 3 ports.
• PLIM QoS is not supported on flex Layer 3 ports.
• All ingress Layer 3 or Switch Virtual Interfaces (SVI) traffic is throttled if flow control is received.

 

Supported Platforms

From Cisco IOS XE Release 17.11.1a, the flex support on Layer 2 and Layer 3 ports is available on the Cisco 1000 Series Integrated Services Routers platform.

interface GigabitEthernet0/1/0

!

interface GigabitEthernet0/1/1

!

interface GigabitEthernet0/1/2

!

interface GigabitEthernet0/1/3

!

interface GigabitEthernet0/1/4

!

interface GigabitEthernet0/1/5

!

interface GigabitEthernet0/1/6

 no switchport

 ip address 10.1.1.5 255.255.255.0

 ip nat inside

 negotiation auto

!

interface GigabitEthernet0/1/7

 no switchport

 ip address 192.168.1.254 255.255.255.0

 ip nat inside

 negotiation auto

C1100#show ip interface brief

Interface              IP-Address      OK? Method Status                Protocol

GigabitEthernet0/0/0   unassigned      YES TFTP   up                    up

Gi0/0/0.100            203.9.6.26   YES manual up                    up

GigabitEthernet0/1/0   unassigned      YES unset  down                  down

GigabitEthernet0/1/1   unassigned      YES unset  down                  down

GigabitEthernet0/1/2   unassigned      YES unset  down                  down

GigabitEthernet0/1/3   unassigned      YES unset  down                  down

GigabitEthernet0/1/4   unassigned      YES unset  down                  down

GigabitEthernet0/1/5   unassigned      YES unset  down                  down

GigabitEthernet0/1/6   10.1.1.5        YES manual up                    up

GigabitEthernet0/1/7   192.168.1.254   YES manual down                  down

ATM0/3/0               unassigned      YES NVRAM  down                  down

Ethernet0/3/0          unassigned      YES NVRAM  down                  down

Vlan1                  unassigned      YES manual down                  down