Hi guys,

This is my first post on the forum, so I apologize if my question was already asked.
I have two proxmox 4.2 (based on debian 8) servers with 4 nics.
1 is for admin network and 2 are dedicated to nas access (via NFS). Those nics are bonded and it works fine. Below is my bond :
auto bond0
iface bond0 inet static
address 192.168.253.199
netmask 255.255.255.0
slaves eth1 eth2
bond_miimon 100
bond_mode 802.3ad
bond_xmit_hash_policy layer2
bond_downdelay 500
bond_updelay 900

However, when I change the mtu of the bond to 9000 (and yhe one of the ywo slave interfaces), the test with ping -s 9000 my_nas_ip does not work

My switch is a netgear GS728TXS with MTU at 9028
My nas is a synology RS814 RP+ with MTU at 9000

I tried with a bridge instead of the bond, and ping -s 9000 my_nas_ip works

Is there anything I have forgotten to configure my bond ?

Thanks
Fernand

First am I understanding you correctly you are only changing one interface and not both on the Bond?

Second Bond interface doesn't mean you are going to get double the download or upload. Connections between hosts will only use one of the 2 interfaces. That being said if you only changed one of the interfaces then it could be possible that the communications between hosts was using the interface you never changed.

Hi
Thanks for your reply

First point : no, I also have to change the switch configration (remove the LACP configuration)

OK, you should only be making the mtu change to the bond interface and you should also ensure that the switch is setup the same.

Hi

ok, I changed the configuration of my bond :
auto eth1
allow-hotplug eth1
iface eth1 inet manual
mtu 8000

allow-hotplug eth2
auto eth2
iface eth2 inet manual
mtu 8000

auto bond0
iface bond0 inet static
address 192.168.253.199
netmask 255.255.255.0
slaves eth1 eth2
bond_miimon 100
bond_mode 802.3ad
bond_xmit_hash_policy layer2
bond_downdelay 500
bond_updelay 900
mtu 8000

root@pve:~# ip link
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq master vmbr1 state UP mode DEFAULT group default qlen 1000
link/ether e4:11:5b:d6:f2:64 brd ff:ff:ff:ff:ff:ff
3: eth1: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 8000 qdisc mq master bond0 state UP mode DEFAULT group default qlen 1000
link/ether e4:11:5b:d6:f2:66 brd ff:ff:ff:ff:ff:ff
4: eth2: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 8000 qdisc mq master bond0 state UP mode DEFAULT group default qlen 1000
link/ether e4:11:5b:d6:f2:66 brd ff:ff:ff:ff:ff:ff
5: eth3: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether e4:11:5b:d6:e2:f2 brd ff:ff:ff:ff:ff:ff
6: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 8000 qdisc noqueue state UP mode DEFAULT group default qlen 1000
link/ether e4:11:5b:d6:f2:66 brd ff:ff:ff:ff:ff:ff
7: vmbr1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
link/ether e4:11:5b:d6:f2:64 brd ff:ff:ff:ff:ff:ff
root@pve:~#

The mtu of my switch is 8028.
It still doesn't work. Is there something I misunderstood ?

What does the switch config look like for this connection?

Hi,

The switch is configured as follow (see sw.png)
- lag with the two ports
- mtu 8028

Attached Thumbnails

 

I see they are part of a trunk. How is the trunk configured?

Hi

Yes that is correct, there is a trunk
See attached files : LACP , ports 11 and 12

Attached Thumbnails

   

OK, but how is the truck configured?

Hi

I think I didn't understand the question.
The trunk is declared with the LACP mode.
There is nowhere else I decladred it.
Have I forgotten something ?

Used the wrong term I'm looking for the Port-channel. Sorry

Hi Thank you for your reply.
See attached file, hope this is what you wanted !

Attached Thumbnails

 

It is a trunk member to what? How is the trunk configured?

I only created the trunk by selecting the ports in the LAG menbership and defining the LACP method.
Have I forgotten somethiong ?