Attempted use of link aggregation and now have lost ethernet connection
Posted: 2020/04/12 19:50:08
I have a (usually) headless server with four ethernet jacks.
Previously, I've only used one (enp3s0) assigned to the server's IP of 192.168.2.20
OK, so I figured that I would try using link aggregation with two of the ethernet ports (enp3s0 and enp5s0) connected to the switch with LACP to improve bandwidth from the server.
I set up a "backup" using a third port (enp6s0) with the IP of 192.168.2.21 and then followed the instructions entitled "Set up LACP bonding interface on CentOS 8" (https://www.snel.com/support/set-up-lac ... -centos-8/)
This instructs disabling and removing NetworkManager (which is what I did in CentOS 6) and specifying scripts in /etc/sysconfig/network-scripts.
I also configured the switch to use link aggregation for those two ethernet ports.
The problem is that now I have no network.
I can bring up the interfaces (link-aggregated enp3s0 and enp5s0, and also the secondary/backup enp6s0):
This brings up each ethernet link but doesn't restore the network connection.
Here are the configuration scripts:
I can copy back the old network scripts that I saved before making the changes and see if that fixes the problem, but I was wondering if there was something simple I'm missing here to make this work. (My sense is that removing NetworkManager isn't the ideal solution for CentOS 8, but at least it's a learning experience.)
Michael
Previously, I've only used one (enp3s0) assigned to the server's IP of 192.168.2.20
OK, so I figured that I would try using link aggregation with two of the ethernet ports (enp3s0 and enp5s0) connected to the switch with LACP to improve bandwidth from the server.
I set up a "backup" using a third port (enp6s0) with the IP of 192.168.2.21 and then followed the instructions entitled "Set up LACP bonding interface on CentOS 8" (https://www.snel.com/support/set-up-lac ... -centos-8/)
This instructs disabling and removing NetworkManager (which is what I did in CentOS 6) and specifying scripts in /etc/sysconfig/network-scripts.
I also configured the switch to use link aggregation for those two ethernet ports.
The problem is that now I have no network.
Code: Select all
[root@ares /]# ifconfig
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 375860 bytes 31101374 (29.6 MiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 375860 bytes 31101374 (29.6 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
Code: Select all
[root@ares /]# ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: enp3s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether 00:25:90:75:92:bc brd ff:ff:ff:ff:ff:ff
3: enp4s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether 00:25:90:75:92:bd brd ff:ff:ff:ff:ff:ff
4: enp5s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether 00:25:90:75:92:be brd ff:ff:ff:ff:ff:ff
5: enp6s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether 00:25:90:75:92:bf brd ff:ff:ff:ff:ff:ff
Code: Select all
[root@ares /]# ip link set enp3s0 up
Here are the configuration scripts:
Code: Select all
[root@ares /etc/sysconfig/network-scripts/]# cat ifcfg-bond0
DEVICE=bond0
Type=Bond
NAME=bond0
BONDING_MASTER=yes
BOOTPROTO=none
ONBOOT=yes
IPADDR=192.168.2.20
PREFIX=24
GATEWAY=192.168.2.1
NM_CONTROLLED=no
BONDING_OPTS="mode=4 miimon=100 lacp_rate=1"
[root@ares /etc/sysconfig/network-scripts/]# cat ifcfg-enp3s0
TYPE="Ethernet"
UUID="69f913d9-7dc2-477f-a440-1515fc39e180"
DEVICE=enp3s0
TYPE=Ethernet
ONBOOT=yes
BOOTPROTO=none
NM_CONTROLLED=no
MASTER=bond0
SLAVE=yes
IPV6INIT=no
[root@ares /etc/sysconfig/network-scripts/]# cat ifcfg-enp5s0
TYPE=Ethernet
BOOTPROTO=none
UUID=c0e558f1-cc68-4609-a9fa-2463ba3c802d
DEVICE=enp5s0
ONBOOT=yes
TYPE=Ethernet
NM_CONTROLLED=no
IPV6INIT=no
MASTER=bond0
SLAVE=yes
[root@ares /etc/sysconfig/network-scripts/]# cat ifcfg-enp6s0
TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=none
DEFROUTE=no
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
IPV6_ADDR_GEN_MODE=stable-privacy
NAME=enp6s0
UUID=ec4b757c-b0ae-430b-a00d-1d3a36c9ed9a
DEVICE=enp6s0
ONBOOT=yes
NM_CONTROLLED=no
IPADDR=192.168.2.21
PREFIX=24
GATEWAY=192.168.2.1
I can copy back the old network scripts that I saved before making the changes and see if that fixes the problem, but I was wondering if there was something simple I'm missing here to make this work. (My sense is that removing NetworkManager isn't the ideal solution for CentOS 8, but at least it's a learning experience.)
Michael