OPNsense Forum

Archive => 24.1, 24.4 Legacy Series => Topic started by: Alpha_DE on June 27, 2024, 09:31:24 PM

Title: OPNsense blocking IP6 traffic
Post by: Alpha_DE on June 27, 2024, 09:31:24 PM
Hey!

A user of my system reported issues access my IMAP server by IPv6.

After some digging around, I found his IPv6 in the firewall-logs

17,,,02f4bab031b57d1e30553ce08e0ec131,vtnet4,match,block,in,6,0x00,0xeb111,64,tcp,6,40,2a01:XXXX:fe02::110,2a00:XXXX:ea05,993,61465,0,SA,3642631772,3523825403,21420,,mss;sackOK;TS;nop;wscale

Rule 17, label 02f4bab031b57d1e30553ce08e0ec131 is the global IPv4/6 Default deny / state violation rule

@16 block drop in log inet all label "02f4bab031b57d1e30553ce08e0ec131"
  [ Evaluations: 1886      Packets: 279       Bytes: 12488       States: 0     ]
  [ Inserted: uid 0 pid 79740 State Creations: 0     ]
@17 block drop in log inet6 all label "02f4bab031b57d1e30553ce08e0ec131"
  [ Evaluations: 1886      Packets: 427       Bytes: 45298       States: 0     ]
  [ Inserted: uid 0 pid 79740 State Creations: 0     ]


I inserted a specific rule for his addresses (beside that the mail server has it's v4/v6 rules allowing access to all mail ports). I see other v6 addresses with the same issue, on v4, it works.

OPNsense 24.1.9_4-amd64

Anybody a good idea how to solve that, I was told it started recently, might be around the 24.1.9 update.
Title: Re: OPNsense blocking IP6 traffic
Post by: Alpha_DE on June 28, 2024, 01:52:17 PM
I did some more checks and the firewall blocks *all* IPv6 traffic with the "Default deny / state violation rule" even when a matching global ACCEPT rule on all interfaces is defined.

@Franco Looks like the packet filter is not processing any IPv6 rules despite that they're shown in the GUI.

Of course, IPv6 is enabled in the Interface settings.
Title: Re: OPNsense blocking IP6 traffic
Post by: abulafia on September 25, 2024, 08:55:30 AM
I seem to be running into the same problem, I e. Opnsense blocking all ipv6 via "default deny" evev though there is ab express allow ipv6 to any rule.
Title: Re: OPNsense blocking IP6 traffic
Post by: Patrick M. Hausen on September 25, 2024, 08:56:46 AM
If you don't show your "allow" rules it's difficult to diaganose, what might be wrong with them.