Advanced Networking Services Guide

Advanced Routing for vCloud Air 2
You can specify static and dynamic routing for each edge gateway in vCloud Air.
To enable dynamic routing, you can configure an edge gateway using the Border Gateway Protocol (BGP) or
the Open Shortest Path First (OSPF) protocol.
This chapter includes the following topics:
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“Specify Global Configuration,” on page 15
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“Add a Static Route,” on page 16
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“Configure BGP,” on page 17
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“Configure OSPF,” on page 18
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“Configure Route Redistribution,” on page 20
Specify Global Configuration
You can configure the default edge gateway for static routes and specify dynamic routing details for an edge
gateway.
Procedure
1 Log in to vCloud Air and navigate to the vCloud Edge Gateway Services UI.
See “Log In and Navigate to Advanced Networking Services,” on page 9 for information.
2 Click the Routing tab and Global Configuration.
3 To enable Equal-cost multi-path routing (ECMP), click Enable next to ECMP.
ECMP is a routing strategy that allows next-hop packet forwarding to a single destination can occur
over multiple best paths. These best paths can be added statically or as a result of metric calculations by
dynamic routing protocols like OSPF or BGP. Multiple paths for static routes can be added by
providing multiple next hops separated by commas in the Static Routes dialog box.
See “Add a Static Route,” on page 16 for information.
The edge gateway utilizes Linux network stack implementation, a roundrobin algorithm with a
randomness component. After a next hop is selected for a particular source and destination IP address
pair, the route cache stores the selected next hop. All packets for that flow go to the selected next hop.
The default IPv4 route cache timeout is 300 seconds (gc_timeout). When an entry is inactive for this
time, it is eligible to be removed from the route cache. The actual removal happens when the garbage
collection timer activates (gc_interval = 60 seconds).
VMware, Inc.
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