VyOS 1.1.8 - High Interface packet drops

virtualization

#1

Hi Guys,
We’re running VyOS in a XenServer 7.1 in the version 1.1.8 (helium):

Version: VyOS 1.1.8
Description: VyOS 1.1.8 (helium)
Copyright: 2017 VyOS maintainers and contributors
Built by: maintainers@vyos.net
Built on: Sat Nov 11 13:44:36 UTC 2017
Build ID: 1711111344-b483efc
System type: x86 64-bit
Boot via: image
Hypervisor: Xen hvm
HW model: HVM domU

We note the following logs:

Jun 6 13:36:37 goc-rjo1-rtr-01 kernel: [1972169.360582] xen_netfront: xennet: skb rides the rocket: 19 slots
Jun 6 13:36:37 goc-rjo1-rtr-01 kernel: [1972169.367073] xen_netfront: xennet: skb rides the rocket: 19 slots
Jun 6 13:36:37 goc-rjo1-rtr-01 kernel: [1972169.370484] xen_netfront: xennet: skb rides the rocket: 19 slots

We applied the Workaround disabling the atributes tcp-segmentation-offload and scatter-gather:

root@goc-rjo1-rtr-01:/home/amascarenhas# sudo ethtool -k eth0
Offload parameters for eth0:
rx-checksumming: on
tx-checksumming: on
scatter-gather: off
tcp-segmentation-offload: off
udp-fragmentation-offload: off
generic-segmentation-offload: off
generic-receive-offload: on
large-receive-offload: off
ntuple-filters: off
receive-hashing: off

But We note a log of drops:

eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether f6:8b:2c:b1:86:e1 brd ff:ff:ff:ff:ff:ff
inet 187.16.245.196/29 brd 187.16.245.199 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::f48b:2cff:feb1:86e1/64 scope link
valid_lft forever preferred_lft forever
Description: OUTSIDE

RX:  bytes    packets     errors    dropped    overrun      mcast
25506620840036 29124559863          0          0          0          0
**TX:  bytes    packets     errors    dropped    carrier collisions**

** 24469733062867 13597270662 0 9475518 0 0**

amascarenhas@goc-rjo1-rtr-01:~$ show interfaces ethernet eth0
eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether f6:8b:2c:b1:86:e1 brd ff:ff:ff:ff:ff:ff
inet 187.16.245.196/29 brd 187.16.245.199 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::f48b:2cff:feb1:86e1/64 scope link
valid_lft forever preferred_lft forever
Description: OUTSIDE

RX:  bytes    packets     errors    dropped    overrun      mcast
25506919570189 29124892319          0          0          0          0
**TX:  bytes    packets     errors    dropped    carrier collisions**

** 24470022472119 13597480238 0 9475710 0 0**

In 10 seconds We had almost 200 packets dropped.

Could you help us find the root cause of it?

Regards,
André Mascarenhas