IPv6 Static Route

An IPv6 static route is a manually configured route that tells the router how to reach an IPv6 remote network. Unlike dynamic routing protocols, Static Routes don’t adjust automatically; they are fixed and must be maintained by the network administrator.

Just like in IPv4, the router needs a route to know where to forward packets. If no dynamic routing protocol is configured, a static route is required to connect different networks.

Let’s take the following topology:

Figure 1 – Initial IPv6 Topology

• PC1 is in the 2001:DB8:1::/64 network.

• PC2 is in the 2001:DB8:2::/64 network.

• R1 and R2 are connected via 2001:DB8:10::/64.

PC1 want to sends traffic to PC2. R1 receives the packet but doesn’t know how to reach the destination network, because 2001:DB8:2::/64 network is not in his IPv6 Routing Table.

Figure 2 – Missing Static Route on R1

Without any static or dynamic route configured, R1 drops the packets and the communication between PC1 and PC2 fails.

To fix the issue, as a network administrator we can configure a IPv6 static route on R1, pointing to R2’s IPv6 address 2001:db8:1::2.

Figure 3 – Adding an IPv6 Static Route on R1

At this point, R1 is now able to forward traffic destinated to 2001:db8:2::/64 to his next hop 2001:db8:10::2.
However, R2 still doesn’t know how to reach the 2001:DB8:1::/64 network.

To complete the communication, we must add a return IPv6 static route on R2, pointing to R1.

Figure 4 – IPv6 Static Route on R2

With static routes now configured on both routers, communication is possible between PC1 and PC2.

Figure 5 – IPv6 Static Route on R1 Working

Traffic from PC1 reaches PC2 by using R1 and R2.

Figure 6 – IPv6 Static Route on R2 for Return Path

Reply packets from PC2 are returned to PC1 using the static route on R2 pointing to R1.

Enough theory let's move into the Cisco IOS Cli to show you every step to configure a IPv6 Static Route.

Figure 7 – Lab Topology IPv6 Static Route

Step 1 – Enable IPv6 Routing

First, you need to know that Cisco router don't have IPv6 routing by default.
We must activate this feature on both routers R1 and R2 using the command ipv6 unicast-routing