dnsmasq failed to send packet: Network is unreachable
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
dnsmasq (Ubuntu) |
Fix Released
|
Undecided
|
Ubuntu Security Team |
Bug Description
the log shows this:
Feb 22 09:37:53 myserver dnsmasq[2259]: failed to send packet: Network is unreachable
repeatedly and frequently.
This is a known bug in dnsmasq and has been fixed upstream (according to the thread quoted below). Apparently it is IPv6 related and triggered by Windows and Mac clients. An extensive thread on the subject is here on the OpenWRT forum:
I think this has been reported in the fallout of the quoted security vulnerabilities. I don't think it is a security vulnerability in itself.
dnsmasq version: 2.80-1.1ubuntu1.2
ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: dnsmasq 2.80-1.1ubuntu1.2
Uname: Linux 5.4.98-219 armv7l
ApportVersion: 2.20.11-
Architecture: armhf
CasperMD5CheckR
Date: Mon Feb 22 09:34:12 2021
PackageArchitec
ProcEnviron:
TERM=xterm
PATH=(custom, no user)
XDG_RUNTIME_
LANG=en_GB.UTF-8
SHELL=/bin/bash
SourcePackage: dnsmasq
UpgradeStatus: Upgraded to focal on 2020-11-15 (98 days ago)
modified.
mtime.conffile.
tags: | added: regression-update |
The (redacted) output of ip addr show is:
1: lo: <LOOPBACK, UP,LOWER_ UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 MULTICAST, ALLMULTI, UP,LOWER_ UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000 6ff:fe32: 613b/64 scope link MULTICAST, UP,LOWER_ UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 6ff:fe32: 613b/64 scope link MULTICAST, UP,LOWER_ UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 d6ba:c144: :1/64 scope global 6ff:fe32: 613b/64 scope link MULTICAST, UP,LOWER_ UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 d6ba:c145: :1/64 scope global 6ff:fe32: 613b/64 scope link NOARP,UP, LOWER_UP> mtu 1480 qdisc noqueue state UNKNOWN group default qlen 1000 NOARP,UP, LOWER_UP> mtu 1480 qdisc noqueue state UNKNOWN group default qlen 1000 5efe:5ce9: ca14/64 scope li...
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,
link/ether ...my mac... brd ff:ff:ff:ff:ff:ff
inet 192.168.1.1/24 brd 192.168.1.255 scope global eth0
valid_lft forever preferred_lft forever
inet6 ...internet ipv6 addr.../64 scope global
valid_lft forever preferred_lft forever
inet6 ...internet ipv6 addr.../64 scope global
valid_lft forever preferred_lft forever
inet6 ...internet ipv6 addr.../64 scope global
valid_lft forever preferred_lft forever
inet6 fe80::21e:
valid_lft forever preferred_lft forever
3: vlan4@eth0: <BROADCAST,
link/ether ...my mac... brd ff:ff:ff:ff:ff:ff
inet ...internet ipv4.../24 brd ...internet ipv4....255 scope global dynamic vlan4
valid_lft 351763sec preferred_lft 351763sec
inet6 fe80::21e:
valid_lft forever preferred_lft forever
4: vlan5@eth0: <BROADCAST,
link/ether ...my mac... brd ff:ff:ff:ff:ff:ff
inet 192.168.2.1/24 brd 192.168.2.255 scope global vlan5
valid_lft forever preferred_lft forever
inet6 fd17:6e78:
valid_lft forever preferred_lft forever
inet6 fe80::21e:
valid_lft forever preferred_lft forever
5: vlan6@eth0: <BROADCAST,
link/ether ...my mac... brd ff:ff:ff:ff:ff:ff
inet 192.168.3.1/24 brd 192.168.3.255 scope global vlan6
valid_lft forever preferred_lft forever
inet6 fd17:6e78:
valid_lft forever preferred_lft forever
inet6 fe80::21e:
valid_lft forever preferred_lft forever
6: sit0@NONE: <NOARP> mtu 1480 qdisc noop state DOWN group default qlen 1000
link/sit 0.0.0.0 brd 0.0.0.0
7: he-ipv6@NONE: <POINTOPOINT,
link/sit ...internet ipv4... peer ...internet ipv4...
inet6 ...internet ipv6 addr.../64 scope global
valid_lft forever preferred_lft forever
inet6 fe80::5ce9:ca14/64 scope link
valid_lft forever preferred_lft forever
8: tunl0@NONE: <NOARP> mtu 1480 qdisc noop state DOWN group default qlen 1000
link/ipip 0.0.0.0 brd 0.0.0.0
9: ipv4-tunnel@NONE: <POINTOPOINT,
link/ipip ...internet ipv4... peer ...internet ipv4...
inet ...internet ipv4.../32 scope global ipv4-tunnel
valid_lft forever preferred_lft forever
inet6 fe80::200: