Multi-homed BGP load sharing

[DutchExport]

Designing a new datacenter network used for webserver hosting. Internet connectivity will be multihomed (we have our own AS) through two ISP's that will each give us two 1Gbit/s connections. The routers are Cisco ASR1002's with 10G backplane and 4Gb of RAM.

The options I have been contemplating are:

1. Bundle the 1G's (EtherChannel) and have one ISP per router with 2Gbit/s of bandwidth. Load sharing/failover will be configured between the two ISP routers.

2. Build out two routers with two ISP's on each. The intent would be to load share/failover across all four connections.

Option 2 would probably not be my prefered option, but been asked to look into this option as it would offer the highest form of redundancy.

Any feedback would be welcome....thanks!

 

[ISPKing]

2 will be pain in the ass to segregate traffic, Best bet is option one. With a 10 gig connection bettween the routers. Then the fun part, ( I am so jealous, I love High Bandwidth Projects) Design an IpSLA/IGP Distribution, Then redistribute into bgp. Add some community's and sir, you are redundant. Option 2 is too tedious and would require Way more route manipulation for appropriate Fialover, unless you get fancy with the IGP.
Let us know what you pick.

CCNP

 

[Quadratic]

I don't think the slight redundancy boost of option 2 will be worth the complexity it would add to the design. Option 1 will give you redundancy at an ISP, gateway and interface level, and I think the overall downtime avoided during periods where Router A and ISP B have simultaneously failed will be offset by the downtime caused simply through operational support and troubleshooting of the more complex design.

CCNP, CCDP

 

[bizhelp]

In theory you could get more usable bandwidth with option 2. Option 1 is easier. Option 2 you can set up to fail automatic (as opposed to what was said in previous posts). You could have some level of load sharing with option 2 although manipulating inbound traffic is always a bit challenging. Pfr / ore is one way of doing the inbound and outbound balancing act.