Out-of-Path with PBR and VRRP Redundant Silver Peak Appliances : Configuring A1 and A2 to Advertise Non-Local Subnets
Configuring A1 and A2 to Advertise Non-Local Subnets
On Appliance B, examine the subnet table by going to Configuration > Subnets.
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Now that Appliance B has learned the remote appliances’ subnets, it automatically places packets with destinations in the learned subnets into the correct tunnels.
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Notice that the subnet where Site A’s end devices reside — the 10.110.33.0 subnet — does not appear in the table.
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This is because the Silver Peaks at Site A don’t have an interface with an IP address in that subnet. As a result, the local Silver Peaks at Site A can’t advertise this subnet to Appliance B. We need to configure A1 and A2 to advertise this subnet to other Silver Peaks.
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To configure A1 to advertise the non-attached subnet.
We’ve already tested connectivity from A1 and A2 to devices on 10.110.33.0 and know that the default next-hop router can reach the devices. If that were not the case, we might have to do some additional configuration like adding a static route to the subnet via a different next hop router.
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On Appliance A1, select Configuration > Subnets. The Subnets tab appears.
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Click Add new subnet.
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Input the subnet and mask: 10.110.33.0/24
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To ensure that it’s advertised with a lower priority than the default, set Metric to 40.
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Select Is Local.
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Select Advertize to peers.
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Click Apply
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Save the changes.
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To configure A2 to advertise the non-attached subnet.
Here, all the steps are the same as for A1, except for the Metric value.
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On Appliance A1, select Configuration > Subnets. The Subnets tab appears.
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Click Add new subnet.
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Input the subnet and mask: 10.110.33.0/24
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Leave Metric at 50 (the default). This ensures that A1’s advertisement for this subnet is preferred over A2’s.
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Select Is Local.
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Select Advertise to peers.
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Click Apply
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Save the changes.
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To verify that Appliance B learned the subnets correctly
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On Appliance B, select Configuration > Subnets.
In the Subnets table, you should see two entries for the 10.110.33.0 subnet — one learned from each of the appliances at Site A.
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Notice that subnets learned from peer 10.110.31.100 ( A1) have a metric of 40, while others were learned with a metric of 50. When Appliance B has a choice of two routes to a subnet, it will prefer to send packets to the device having the lower metric. For subnet 10.110.33.0, Appliance B will always route packets to A1 because it has the lower metric.
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If Appliance A1 goes down, the subnets it advertises disappear from the table, and Appliance B will use the route advertised by peer A2 (10.110.31.100).
Please send comments or suggestions regarding user documentation to techpubs@silver-peak.com.