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IDProjectCategoryView StatusLast Update
0004687unrealircdpublic2021-06-27 18:52
Reportersyzop Assigned To 
Status confirmedResolutionopen 
Product Version4.0.3.1 
Summary0004687: Linking to server by hostname: try IPv4 address first and then IPv6
DescriptionIdeally, when connecting to a server by hostname with both an IPv4 and IPv6 record then UnrealIRCd should try IPv6 first and then IPv4. Right now it tries IPv6 and then if that fails, it gives up.
To workaround it currently you have to force IPv4 either by specifying an IPv4 link::bind-ip or setting an IP explicitly in link::outgoing::hostname.

Of course this "only" matters if the IRCd is IPv6-capable (like many) but the host is not truely connected to an IPv6 network (very common as well) and the remote host has an IPv6 address (right now.. not so common).
TagsNo tags attached.
3rd party modules


has duplicate 0005921 closedsyzop Unreal tries to link over IPv6 on systems where it's not available 



2021-06-27 18:52

reporter   ~0022047

Here's a ugly diff to illustrate how this could the ipv4 fallback could be tackled: if the server cannot be reached over v6 it attempts to resolve and reconnect via v4. This would solve the issue for 99% of the ipv4-only servers.
ipv6-fix.diff (2,336 bytes)

Issue History

Date Modified Username Field Change
2016-05-22 21:27 syzop New Issue
2016-05-22 21:29 syzop Description Updated
2016-05-22 21:29 syzop Status new => confirmed
2021-06-26 19:49 syzop Relationship added has duplicate 0005921
2021-06-27 18:52 Polsaker Note Added: 0022047
2021-06-27 18:52 Polsaker File Added: ipv6-fix.diff