Take the 2-minute tour ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.

We have a CentOS installation, The machine has the IPv6 Address fe80::fc54:ff:fea1:563/64.

What address should I specify within my Windows machine so I am able to access the CentOS machine?

We are unable to enable IPv4 or change the address on the CentOS machine because of software loaded on the machine, If we change it we don’t know what impact this will have, so I need to stay away from this method.

share|improve this question
    
Are your Windows machine and the CentOS machine on the same LAN? Also, can you confirm the :: between fc54 and ff in the address above? I suspect that should just be the one colon, and it makes a difference. –  MadHatter Jun 4 at 8:52
    
Hi, Yeah there on the same lan. appoligies there is only 1 colon, fe80::fc54:ff:fea1:563/64 –  Matt Leyland Jun 4 at 9:11
    
Fixed - thanks for the clarification. If you've followed Sander's (excellent) advice below and it's still not working, you may have a v6 firewall issue on the CentOS box. If that's so, could you cut-and-paste the output of ip6tables -L -n -v into your question, and clarify which port(s) and protocol(s) you're trying to access the system on. –  MadHatter Jun 4 at 9:37

1 Answer 1

up vote 3 down vote accepted

This is a link-local address. They are great for protocols that do stuff automatically on the LAN, but they are not so useful for manual usage.

As the name implies those addresses are local to the link. To be able to access that link-local address from a windows machine you will have to determine the interface number that connects to the link you want on the windows machine. Then you can tell windows to use that link-local address on that specific interface.

For example, let's say the interface number on the windows machine is 42. Then on that windows machine you can connect to

fe80::fc54:ff:fea1:563%42

To reach the link-local address of that CentOS box.

It would be much easier if you could give that box a normal address besides that link-local address...

share|improve this answer
    
Sander, I agree with nearly everything you've said above about link-local addresses (+1 from me) but I don't accept that they're any less useful than globally-valid addresses when the machines looking to communicate are on the same LAN. If the Windows box is single-homed, then surely he should be able to use the CentOS machine's link-local address without any further ado? That said, I know you know quite a lot about ipv6, so I would value your clarification if there are reasons to dislike link-local that I don't yet know! –  MadHatter Jun 4 at 9:34
    
Good answer. Could be slightly better if you mentioned how to find the interface number. In case one need to access a webinterface on a link-local address from a browser without support for interface specification in the URL, or in case one need to access a link-local address on a device on a different network segment, I find ssh port forwardings to be the easiest method to access such link-local addresses. –  kasperd Jun 4 at 9:39
    
The thing that makes link-local addresses less useful for manual usage is that you always need the interface id. Not all browsers support the % notation, and every system can use different interface ids. So specifying a href to a link-local address needs to adjust the href to include the interface id of the right interface on the viewers system, which you can't know remotely. For custom software on a system it is easier, but i.e. Browser usage is complex. –  Sander Steffann Jun 4 at 16:34

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.