Lapukhov: BGP as IGP
-
Upload
blueberrymaiden -
Category
Documents
-
view
19 -
download
1
description
Transcript of Lapukhov: BGP as IGP
-
Global Networking Services Team, Global Foundation Services, Microsoft Corporation
Routing Design for Large Scale Data Centers:
-
2
-
3
Problem Statement
-
4
100s thousands of servers 10G NICs
Aware of the network Explicit parallelism Example: Web Index computation
-
5
Query Background
Query
Background
-
6
The simpler the better
Single protocol Simple behavior Wide vendor support
-
7
What We Started With
-
8
Folded on diagram
ECMP Based
-
9
-
10
-
11
Why BGP over IGP
-
12
Better vendor interoperability Less state-machines, data-structures etc
Use for unequal-cost Anycast load-balancing solution
-
13
BGP RIB structure is simpler compared to link-state LSDB Clear picture of what sent where (RIBIn, RIBOut)
E.g. link failures have limited propagation scope More stability due to reduced event flooding domains
-
14
Not a problem with automated configuration generation
Is not our primary goal anyways, few seconds are OK Practical convergence in less than a second
-
15
The New Approach
-
16
Broadcast storms Hard to troubleshoot
Bandwidths scales up, and not out
-
17
-
18
-
19
No need to buy higher-radix boxes Cheaper infrastructure
No interworking/redistributions etc
-
20
Details and Design Choices
-
21
We rely on ECMP for routing Needed for Anycast prefixes
Simplifies path hiding at WAN edge (remove private AS) Simplifies route-filtering at WAN edge (single regexp)
-
22
Allow AS in
-
23
AS_PATH Multipath Relax
Allow AS In
Fast eBGP Fall-over
Remove Private AS
-
24
Otherwise: Route Black-Holing on link failure!
-
25
Otherwise: Route Black-Holing on link failure!
-
26
This made it perfect choice for us!
-
27
Questions?