Is GLBP right choice for introducing redundancy ? 1

[anrovla]

Have 2811 router with 2 serial i/f in balancing mode (same metrics, only statisc routes) connecting LAN1 to LAN2. Need to add redundancy 'on router' lever, i.e. to be protected if one router goes down in LAN1. Hosts in LAN1 can not be altered in termfs of changing default gataway and I must keep BOTH serial lines up (so no VRRP or HSRP). Is GLBP right choice for introducing redundancy ? I.e. 2 x 2811 with 1 serial i/f each over GLBP ? Any advice, impact on static routing, field expiriance ?

 

[leedsit]

Hi,

A little confused about the "I must keep BOTH serial lines up (so no VRRP or HSRP)" comment. As far as I know GLBP is exactly the same as HSRP execept the clients usage of a default gateway is balanced.

Im sure if you dont need to load balance your hosts to a default gateway, then HSRP/VRRP will do the trick.

LEEroy
MCNE6,CCNP,CWNA,CCSA,Project+

 

[anrovla]

Now I am confused. As far as I understand, HSRP/VRRP over 2 routers with one serial each, all traffic will go via 'active' router, while 'backup' router will be left in case of outage. Right ? What I need is traffic from LAN1 to be balanced over TWO serial lines, so in case of router outage, I'll lose only half of the bandwidth, allowing all services to be still alive ...

Anrovla

 

[KiscoKid]

Then GLBP is a good choice if you deploy static routing on the LAN and WAN.

If you use dynamic routing, you should be able to achieve the same thing as GLBP but it's generally a little more complex to get working than GLBP.

 

[anrovla]

what exactly do you refer by 'dynamic routing' ?

Anrovla

 

[KiscoKid]

dyanmic routing includes protocols like OSPF, BGP, EIGRP etc. They will detect routing failures and re-route traffic automatically via your redundant link. With proper configuration, they will load-balance across all active links.

They are generally more complex to setup than protocols like GLBP.

 

[anrovla]

But of course, in case of ONE router with 2 serial links (my current case). If I have 2 routers with ONE serial each, OSPF running, VRRP enabled, then ANY packet comming from LAN1 with VIP (virtual IP of VRRP group) as destination, will be forwarded by 'active/master' router via ONE serial link. Second (pasive / backup) router will never get packet that can be forwarded via it's own serial, right ? Means ALL hosts in LAN1 with default gateway pointing to VIP, will be served by active router in VRRP group ...

Anrovla

 

[KiscoKid]

yes everyone will have the same VIP but GLBP will allow you to load-balance over 2 serials on the same router. As will any dynamic routing protocol.

 

[anrovla]

... as well as GLBP will load balance between TWO routers with ONE serial, and VRRP/HSRP will not, right ?

 

[KiscoKid]

correct