Here I'd like to share a common reason for this issue. in default, these series of CE switches don't support IPV6 routes with a prefix longer than 64, so normally, if there are such IPV6 routes in the routing table, these routes couldn't be added into forwarding chip successfully, in this case, you must configure the command "assign forward ipv6 longer-mask resource ipv6-address-number" to assign resource for such IPV6 routes.
below is the introduction for this command:
Usage Guidelines
Usage Scenario
Before configuring IPv6 addresses with a prefix longer than 64 on the CE8860EI, CE7855EI, CE7850EI, CE6855HI, CE6850U-HI, CE6851HI, CE6850HI, and CE5850EI, you must run the assign forward ipv6 longer-mask resource command to configure the maximum number of these IPv6 addresses.
Precautions
After the maximum number of IPv6 addresses with a prefix longer than 64 is configured using the assign forward ipv6 longer-mask resource command, the number of routes on IPv6 and IPv4 network segments is reduced.
- When the value of ipv6-address-number is 256, the number of routes on the IPv6 network segment is reduced by 2048 and that on the IPv4 network segment by 1024.
- When the value of ipv6-address-number is 512, the number of routes on the IPv6 network segment is reduced by 2048 and that on the IPv4 network segment by 2048.
- When the value of ipv6-address-number is 1024, the number of routes on the IPv6 network segment is reduced by 2048 and that on the IPv4 network segment by 4096.
- When the value of ipv6-address-number is 2048, the number of routes on the IPv6 network segment is reduced by 4096 and that on the IPv4 network segment by 8192.
