Problem with adding secondry vlan interface on extreme C5G124-24P2 - Could not set the interface network.


Hi all,

I am trying to set a secondary interface IP on VLAN 1. Due to business changes I needs to move away from their Class C network to a class B network. I am adding a secondry IP to be able to route between old and new network.

Here is what happens:
DetNet_Router(su)->router
DetNet_Router(su)->router>enable
DetNet_Router(su)->router#configure
Enter configuration commands:
DetNet_Router(su)->router(Config)#interface vlan 1
DetNet_Router(su)->router(Config-if(Vlan 1))#ip address 172.20.0.1 255.255.0.0 secondary
Could not set the interface network.

The primary interface on this vlan is 192.168.0.1 255.255.240.0

What am I doing wrong?

Thank you in advance.

5 replies

Userlevel 6
Just guess: the IP you are adding is already on different vlan?
Pala, Zdenek wrote:

Just guess: the IP you are adding is already on different vlan?

I figured the same thing out. I manged to add 172.20.0.2.

I however cant find where 172.20.0.1 resides. Is there a command that I can run to find it?

Thanks for the reply


Pala, Zdenek wrote:

Just guess: the IP you are adding is already on different vlan?

tried show interface - displays all vlan interfaces but the 172.20.0.1 is on none of them.
Just as a side note to all.

It looks like you have to shut down the interface before you can add secondary IP.

this is achieved by command "shutdown" when in router config mode.

you can start it again with command "no shutdown"
Userlevel 4
show conf router
#Router Configuration
router
enable
configure
interface vlan 100
ip address 192.168.100.1 255.255.255.0
no shutdown
exit
interface vlan 200
ip address 192.168.200.1 255.255.255.0
no shutdown
exit
exit
exit
exit
!

(su)->router>en
(su)->router#conf
Enter configuration commands:
(su)->router(Config)#interface vlan 200
(su)->router(Config-if(Vlan 200))#ip address 10.58.166.1 255.255.255.0 secondary

show config router
#Router Configuration
router
enable
configure
interface vlan 100
ip address 192.168.100.1 255.255.255.0
no shutdown
exit
interface vlan 200
ip address 192.168.200.1 255.255.255.0
ip address 10.58.166.1 255.255.255.0 secondary
no shutdown
exit
exit
exit
exit
!

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