Comments on: Configure Multiple IP Address on a Cisco Router Interface

By: Jesse Smith

Jesse Smith — Wed, 27 Jul 2011 16:23:03 +0000

the effect is that you can have the router accessible by multiple subsets. should not change much at all.

if u are trying to trace using the secondary i beleave you need to change the routing table to match the secondary network number. something like

ciscorouter# conf t
ciscorouter(config)# int fa0/1
ciscorouter(config-if)# ip address 192.168.1.1 255.255.255.0
ciscorouter(config-if)# ip address 192.168.2.1 255.255.255.0 sec
ciscorouter(config-if)# exit
ciscorouter(config)# ip route 192.168.2.0 255.255.255.0 192.168.1.1

that should forward traffic properly

By: ali

ali — Tue, 19 Jul 2011 13:58:09 +0000

Hi
If you want assign the ip address,subnet Mask and default Gateway
This is IP Address and Subnet Mask

R1(config)#int g 0/1
R1(config-if)#ip address 1.1.1.1 255.0.0.0
R1(config-if)#exit

Defautl Gateway is

R1(config)#ip route 0.0.0.0 0.0.0.0 1.1.1.2

R1(config)#ip default-gateway 1.1.1.2

Secondary IP is

R1(config)#int G 0/1
R1(congig-if)#ip address 1.1.1.1 255.0.0.0
R1(config-if)#ip address 1.2.1.1 255.0.0.0 secondary
R1(config-if)#ip address 1.3.1.1 255.0.0.0 sedondary
R1(config-if)#ip address 1.4.1.1 255.0.0.0 secedonary
R1(config-if)#n shutdown
R1(config-if)#exit

For Every Network their is a seprate gateway you need to assign,it is depend on your subnet and isp assigned Gateway.

By: Caio

Caio — Mon, 18 Jul 2011 14:51:24 +0000

Hi,

If I use secondary IP of different subnets and in the same interface (e.g Vlan1) I use standby IP (HSRP), may I have conflict?

Regards,

By: Mf Moyo

Mf Moyo — Tue, 21 Dec 2010 05:53:00 +0000

What is the effect of having many subnets on a single router interface? Does it affect browsing speed or increase latency?

By: Boni

Boni — Thu, 15 Jul 2010 08:47:32 +0000

Hi..

My ISP has given me details below:
IP: xxx.xxx.xxx.xxx
SM: xxx.xxx.xxx.xxx
Gateway: xxx.xxx.xxx.xxx
DNS1: xxx.xxx.xxx.xxx
DNS2: xxx.xxx.xxx.xxx

How can I enter this information on a router interface?

Regards,

By: Robinson A

Robinson A — Wed, 07 Jul 2010 15:18:36 +0000

Hi,

Is it possible to Configure same IP Address in the Different interfaces on a Router.

Thanks & Regards,
Robinson A

By: boyd

boyd — Tue, 29 Jun 2010 10:40:26 +0000

What are the IP and subnet assigned to the primary and secondary address. Its possible that your secondary IP doesnt have a route to the internet or it doesnt participate on the routing protocol that you use. If that is the case, you need to setup a static route for the secondary IP.

By: suhail

suhail — Fri, 29 Jan 2010 11:40:39 +0000

no answer of my qustion

By: Blake Payne

Blake Payne — Sat, 07 Nov 2009 22:32:09 +0000

Jon M,
It seems like maybe the packets TTL (time to live) is expiring before it gets there. Unless someone has something else, that’s all I could think of.

By: Jon M

Jon M — Tue, 06 Oct 2009 11:15:19 +0000

I’ve configured several secondary IP addresses on my 1811, and for some reason only the primary is reachable from the internet. Any advice? They are all on the same subnet, and when doing a trace route on the secondary IPs it times out at the last hop before my router.