The ip link set command which create the veth pair is not setting mtu on both
peers
example:
vm 106 is on a bridge with mtu 9000
222: tap160i1: <BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP> mtu 9000 qdisc
pfifo_fast master fwbr160i1 state UNKNOWN group default qlen 1000
223: fwbr160i1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state
UP group default qlen 1000
224: fwpr160p1@fwln160i1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 qdisc
noqueue state UP group default qlen 1000
225: fwln160i1@fwpr160p1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc
noqueue state UP group default qlen 1000
fwpr160p1@fwln160i1 is correctly created with mtu 9000
but
fwln160i1@fwpr160p1 is created with mtu 1500.
(and then vmbr106i1 is lowered to 1500 too).
This is doing network problem, as tap160i1 is mtu9000.
After this patch:
222: tap160i1: <BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP> mtu 9000 qdisc
pfifo_fast master fwbr160i1 state UNKNOWN group default qlen 1000
223: fwbr160i1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 qdisc noqueue state
UP group default qlen 1000
224: fwpr160p1@fwln160i1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 qdisc
noqueue state UP group default qlen 1000
225: fwln160i1@fwpr160p1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 qdisc
noqueue state UP group default qlen 1000
---
src/PVE/Network.pm | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/PVE/Network.pm b/src/PVE/Network.pm
index 3421532..8dfc9c2 100644
--- a/src/PVE/Network.pm
+++ b/src/PVE/Network.pm
@@ -291,7 +291,7 @@ sub veth_create {
# create veth pair
if (! -d "/sys/class/net/$veth") {
- my $cmd = "/sbin/ip link add name $veth type veth peer name $vethpeer
mtu $bridgemtu";
+ my $cmd = "/sbin/ip link add name $veth mtu $bridgemtu type veth peer
name $vethpeer mtu $bridgemtu";
$cmd .= " addr $mac" if $mac;
system($cmd) == 0 || die "can't create interface $veth\n";
}
--
2.11.0
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