How to change LAN defautl gateway (ISP) automatically to another gateway when goes down?

[gravis0516]

Hi:

I was just wondering, if its possible this scenario. I got a client that has two buldings; each of this buildings are going to have one blades systems for virtualization of the servers, synchronizing constantly using a software that makes this. Each bulding has the same ISP provider but diferrent lines and different public ip addresses. The two buildings are gonna go to one of this line to the internet and the other is for backup only, in case the default one goes down. This can be done manually by changing in the DHCP the default gateway, but the client is asking if this can be done automatically, because down time for them cost thousand of dollars. The scenario in infraestructure is = two buildings having domain controller on each one, one DHCP server, they are going to be talking via a T1 line Point-to-Point. One of the buildings has a T1 line to the internet with a public address and a ISA Server for routing and firewall and the other building the same thing. Any help will be appreciated.

Thank You

gravis0516

[milan.kulik · Accepted solution]

Hi,

wouldn't there an HSRP running between the gateway routers with tracking the Internet line status be a solution?

See http://www.cisco.com/application/pdf/paws/13780/6.pdf

for details.

HTH,

Milan

[gravis0516]

Hi:

Thank you for the fast reply. I was reading about the HSRP protocol, and it seems to be what i'm looking for, but my question is which router o switch layer 3 models would move this kind of protocol??

Thank you

gravis0516

[milan.kulik]

Hi,

HSRP is a Cisco proprietary protocol. Most of Cisco routers and L3 switches are providing it.

The product/IOS documentation should say you if your router is HSRP capable.

If you are looking for similar features on other vendor devices, VRRP is a standardized version of such a protocol with very similar features.

BR,

Milan

[RAMACHANDRA R]

Hi,

If two sites are connected via T1 line , then you should be having Cisco routers at both side, enable default route with tracking of Primary Internet Service provider next hop IP address.

HTH

Rama