MTU not set on 'tunnel' interfaces
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
ifupdown (Ubuntu) |
New
|
Undecided
|
Unassigned |
Bug Description
Setting MTU via /etc/network/
iface HYDRUS inet tunnel
mode gre
address 10.170.1.4
netmask 255.255.255.254
endpoint 10.0.0.1
dstaddr 10.170.1.5
local 10.255.255.12
mtu 1472
37: HYDRUS: <POINTOPOINT,
link/gre 10.255.255.12 peer 10.0.0.1
It seems to calculate the MTU based on the parent interface's MTU and ignore the directive. man 5 interfaces indicates that mtu should be a valid option for interfaces of type 'tunnel'. I have worked around this with an 'up' directive to manually set the MTU. Upon examining the ifupdown.nw source, it appears that MTU is never set for 'tunnel' type interfaces. Please rectify or remove it from the documentation.
$> lsb_release -rd
Description: Ubuntu 12.04.1 LTS
Release: 12.04
$> apt-cache policy ifupdown
ifupdown:
Installed: 0.7~beta2ubuntu8
Candidate: 0.7~beta2ubuntu8
Version table:
*** 0.7~beta2ubuntu8 0
500 http://
100 /var/lib/