12-23-2002 05:19 AM - edited 03-02-2019 03:46 AM
Hi,
I have a router with 2 lan interfaces.
I need to define a backup interface (LAN) for the same IP address as the primary one.
Is it possible? How?
thank's
Lior
Solved! Go to Solution.
12-23-2002 05:59 AM
These two router's will be on the same wire/segment.
Depending on what platform you can configure mutiple groups on a single interface. The simplest way is to config
R1 - Active
standby 1 priority 140 preempt
standby 1 authentication LAB
standby 1 name Live_Net
standby 1 ip 10.1.10.254
R2 - Standby
standby 1 priority 110 preempt
standby 1 authentication LAB
standby 1 name Live_Net
standby 1 ip 10.1.10.254
In the above R1 is active and if this interface fails then, R2 will flip over and resume traffic flow, You can also configure multple groups on an interace eg:
Int VLAN 10
standby 2 priority 140 preempt
standby 2 ip 10.1.10.200
standby 1 priority 110 preempt
standby 1 ip 10.1.10.254
So on once side active IP will be the end users Default G/W of 10.1.10.200 and the the other end the Default G/W will use 10.1.l0.254, so this creates a load balancing scenario
You could also track other interafaces on a router with "standby 1 track"
12-23-2002 05:30 AM
I do not believe this is possible. The router should prevent you from using the same IP address on another interface. HSRP will perform similar functionality to what you are trying to do
12-23-2002 05:39 AM
What about using the backup interface command?
01-13-2003 08:28 PM
Hi,
I have assigned the same ip address to two ethernet interfaces of cisco 7200 router using the back up interface command.But when the active link goes down,standy link doesnot come up automatically. This issue to due to ARP.When i delete the ARP in the PC,this is possible.
Can anyone help me out to solve this problem.
tselvan
12-23-2002 05:47 AM
The best bet has been mentioned, is to use the HSRP as it can provide laod balancing capabilites with MHSRP etc..
12-23-2002 05:50 AM
But, can I use the HSRP on the same router?
an d what if I have two routers with tha same configuration?
12-23-2002 05:59 AM
These two router's will be on the same wire/segment.
Depending on what platform you can configure mutiple groups on a single interface. The simplest way is to config
R1 - Active
standby 1 priority 140 preempt
standby 1 authentication LAB
standby 1 name Live_Net
standby 1 ip 10.1.10.254
R2 - Standby
standby 1 priority 110 preempt
standby 1 authentication LAB
standby 1 name Live_Net
standby 1 ip 10.1.10.254
In the above R1 is active and if this interface fails then, R2 will flip over and resume traffic flow, You can also configure multple groups on an interace eg:
Int VLAN 10
standby 2 priority 140 preempt
standby 2 ip 10.1.10.200
standby 1 priority 110 preempt
standby 1 ip 10.1.10.254
So on once side active IP will be the end users Default G/W of 10.1.10.200 and the the other end the Default G/W will use 10.1.l0.254, so this creates a load balancing scenario
You could also track other interafaces on a router with "standby 1 track"
01-14-2003 01:32 AM
Hi,
How about using the same MAC Address on both the interfaces? I think this works? PC Does not require ARP entry to timeout.
If something rellay restrict you from configuring HSRP, you can go ahead with setting same MAC Address manually, this should work.
Regards,
01-15-2003 01:46 AM
Hi subbarao,
Thanks for the information.I assigned the same mac address,it works fine.
Rgds,
tselvan
01-15-2003 08:09 AM
One note to make, standby will decrement the priority by 10 points by default. If you track an interface, with the priority different by 30 points, it will not switch over to the standby interface. It will work during a complete failure of the interface, because of the lost communication between interfaces. A value of 5 points difference will cause the priority feature to function properly.
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