How to configure already statically routed IPv6 block on CentOS 7

Dr.H asked:

My question is very simple yet I didn’t find a solution, probably because of my lack of networking knowledge.

I have a dedicated server and I manipulate it through IPMI remotely. Recently I asked for IPv6 support from the administrator here is what I got
respond

IP Range: 2604:881:39c::/48 has been statically routed to your server.
I tried to assign an IP within this block (2604:881:39c::2) to my server then I found they didn’t provide gateway address. Then I asked

Me: Can I ask what is the ipv6 gateway address?
Admin: This is a static route and does not include a gateway. All IPs are routed to your server.

I tried to configure it but I have totally no idea what the right path is. Because I don’t know much about IPv6 addressing and what this “STATIC ROUTE” on upstream means here. What I have got so far is I randomly pick an address 2604:881:39c::2 and set 2604:881:39c::1 to be the gateway. Here:

TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=none
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=no
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
IPV6_ADDR_GEN_MODE=stable-privacy
NAME=eno1
UUID=6d049769-68a1-4631-83d4-46b0f3afdf59
DEVICE=eno1
ONBOOT=yes
IPADDR=XX.XXX.XX.XX
PREFIX=30
GATEWAY=XX.XXX.XX.XX
DNS1=8.8.8.8
IPV6_PRIVACY=no
ZONE=public
DNS2=2001:4860:4860::8888
IPV6ADDR=2604:881:39c::2/48
IPV6_DEFAULTGW=2604:881:39c::1
IPV6_PEERROUTES=no

When I do tracepath6, I have:

PING ipv6.google.com(dfw28s04-in-x0e.1e100.net (2607:f8b0:4000:815::200e)) 56 data bytes
From myhostname (2604:881:39c::2) icmp_seq=1 Destination unreachable: Address unreachable
From myhostname (2604:881:39c::2) icmp_seq=2 Destination unreachable: Address unreachable
From myhostname (2604:881:39c::2) icmp_seq=3 Destination unreachable: Address unreachable
From myhostname (2604:881:39c::2) icmp_seq=4 Destination unreachable: Address unreachable
From myhostname (2604:881:39c::2) icmp_seq=5 Destination unreachable: Address unreachable
From myhostname (2604:881:39c::2) icmp_seq=6 Destination unreachable: Address unreachable
From myhostname (2604:881:39c::2) icmp_seq=7 Destination unreachable: Address unreachable
From myhostname (2604:881:39c::2) icmp_seq=8 Destination unreachable: Address unreachable

It seems like it resolved the DNS successfully but had no route to the global internet. Also, I tried ip -6 route add but it didn’t work.

Does anyone have ideas about this? I am stuck.

My answer:


If the network admin really refuses to give you the gateway address, you can just ping the IPv6 all routers multicast address, and it will respond. You will then know at least one of its addresses.

For example:

[[email protected] ~]# ping6 -c 1 ff02::2%eno1
PING ff02::2%eno1(ff02::2%eno1) 56 data bytes
64 bytes from fe80::5054:ff:fefc:d4da%eno1: icmp_seq=1 ttl=64 time=0.265 ms

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