Redundancy between L2 device and Router

[Rajeev Ranjan]

Dear Friends,

I want redundancy in my network. Kindly find the network diagram.

Whats the challenges in proposed network diagram. Kindly help me to implement the proposed network schenario.

Router1 goes to ISP A and Router 2 goes to ISP B. BGP is running in AS 1.HSRP is running on both the routers. Firewall 1 & 2 are in Active Standby mode. Local network is 192.168.1.0/24.

For redundancy what should I do. Kindly suggest.

IP Scheme for running topology:-

192.168.1.251-Firewall1

192.168.1.252-Firewall2

192.168.1.253-Virtual ip for firewall

192.168.1.241-Router1 Gi0/1

192.168.242-Router2 Gi0/1

192.168.1.243-Virtual IP for Routers.

Thanks,

[jdewberr]

Hi Rajeev,

I am assuming this is your LAN setup and you have not added in the WAN/BGP part.

The first thing to do here is know where you are blocking and where you are forwarding via STP. 

Have for yourself readily available a visio articulating the output of

show cdp neighbors

show spanning-tree root

show spanning-tree blocked

per vlan --> doing this will put you into the habit of knowing where you are blocking and where you are forwarding and not coming up with some kind of scheme that's hard to manage and/or articulate on a visio type diagram.  Next to each port do the following

stp blocking in red text BLK

stp root port in green ROOT

stp designated in blue DES

A few questions:

I see the 2x connections to Router1 and Router2.  Is that vPC?

Are the 2x connections to Router1 and Router2 some kind of failover/track mechanism? 

If not...articulate the purpose of the 2x links on Router1 and Router2

A little bit needs to be known here about the L2 devices & topology.  Keys to success here are to know where you're rooting,designated and blocking.  Then make sure you can get arp to & from where you're wanting packets to go.

[viswamin]

Hi Rajeev,

Since you are looking for redundancy, advantage is you will have backup but that comes with a problem as well. It will create Loop. so ensure that you have no loops in your topology.

STP will help preventing Loops at L2.  so ensure that you have the right and effective port in forwarding / blocking ports.

at L2, I guess you are having Gateway Redundancy protocol . so R1 and R2 can act as a default gateway for your lan enviroment. if you have multiple Vlan's inside your lan, you can balance the load between R1 and R2 using GLBP.

Also, you can load balance the traffic at L2 by making some switch as Root for some vlan and some other switch as the Root for some other vlan. that way you can use the switches effectively as well.

HTH

-Vijay