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Fix various name server config issues
Closed, ResolvedPublicBUG

Description

When a PPPoE session is connected, pppd will update /etc/resolv.conf regardless of system name-server option unless no-peer-dns is set. This is because pppd vendors scripts /etc/ppp/ip-up.d/0000usepeerdns and /etc/ppp/ip-down.d/0000usepeerdns, which updates /etc/resolv.conf on PPPoE connection and reverts the change on disconnection.

There is a typo in /etc/dhcp/dhclient-enter-hooks.d/04-vyos-resolvconf, which misspells variable name new_dhcp6_name_serversasnew_dhcpv6_name_servers. This causes IPv6 name server entries in vyos-hostsd` not updated when dhclient receives nameservers from DHCPv6.

Regular expressions in scripts under /etc/dhcp/dhclient-enter-hooks.d and /etc/dhcp/dhclient-exit-hooks.d/ are not enclosed in ^$, so those IPv4 related branches (like BOUND) could be mistakenly executed when an IPv6 reason (like BOUND6) is given.

Details

Difficulty level
Easy (less than an hour)
Version
1.4,1.3
Why the issue appeared?
Will be filled on close
Is it a breaking change?
Perfectly compatible
Issue type
Bug (incorrect behavior)

Event Timeline

Created PR to fix this: https://github.com/vyos/vyos-1x/pull/1656
This issue also exists in 1.3 though I didn't backport it.

There is also a service called "pppd-dns.service" that references "/etc/ppp/ip-down.d/0000usepeerdns", this service is enabled by default and fails on new installs.
It should be disabled and optionally, the file removed too.

This on the 1.3 branch mind you

Viacheslav changed the task status from Open to Needs testing.Jan 25 2023, 8:20 AM
n.fort claimed this task.
n.fort added a subscriber: n.fort.

I'm marking this task as resolved, since it's been in 'Needs Testing' status for more than 6 months