I use an Odroid device with Debian 11 and kernel 6.1 as my NAS. I tried older kernel versions (5.10 and such) with no difference.
I recently connected a second network interface, so now I have got:
- eth0 (the built-in 1Gb/s Ethernet port), IP: 192.168.1.155.
- eth1 (USB 3.0 1Gb/s Ethernet card), IP: 192.168.1.156.
In netplan, devices are configured to use a single IP address, eth0:
addresses:
- 192.168.1.155/32
eth1:
addresses:
- 192.168.1.156/32
ifconfig:
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.1.155 netmask 255.255.255.255 broadcast 0.0.0.0
inet6 X prefixlen 64 scopeid 0x20<link>
ether X txqueuelen 1000 (Ethernet)
RX packets 23767007 bytes 1991691527 (1.8 GiB)
RX errors 0 dropped 4484 overruns 0 frame 0
TX packets 39239638 bytes 58168353216 (54.1 GiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
device interrupt 24
eth1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.1.156 netmask 255.255.255.255 broadcast 0.0.0.0
inet6 X prefixlen 64 scopeid 0x20<link>
ether X txqueuelen 1000 (Ethernet)
RX packets 2532258 bytes 202799128 (193.4 MiB)
RX errors 1 dropped 2821 overruns 0 frame 0
TX packets 1164474 bytes 16121299674 (15.0 GiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
ip route:
default via 192.168.1.1 dev eth0 proto dhcp src 192.168.1.155 metric 100
192.168.1.0/24 dev eth1 proto kernel scope link src 192.168.1.156
192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.155
192.168.1.1 dev eth0 proto dhcp scope link src 192.168.1.155 metric 100
It seems like my USB3.0 eth1 interface is slower (around 830Mb/s max outgoing speed) vs eth0 (around 980Mb/s).
I'm always accessing my NAS by 192.168.1.155 (so it should go to eth0 on NAS), but I noticed reduced speeds. After checking ipconfig, I noticed that TX packets increase on the wrong interface.
This seems to be very random. Generally, I can fix all the reduced speed issues by shutting down eth1: sudo ip link set eth1 down.
Sometimes, when I am accessing NAS by 192.168.1.156 it also links to the wrong interface. Instead of getting reduced speed, I get the full one of eth0, instead of eth1.
I am using Windows SMB, and Filezilla's SFTP to test these speeds.
So my question is, what I'm doing wrong? Why linux just selects a single interface (randomly), and uses it for my requests on both IPs: *.155 and *.156?
EDIT:
I think I solved the problem. I found some useful information here: https://unix.stackexchange.com/questions/4420/reply-on-same-interface-as-incoming
Step 1:
sysctl -w net.ipv4.conf.default.arp_filter=1
sysctl -w net.ipv4.conf.all.arp_filter=1
sysctl -w net.ipv4.conf.default.arp_ignore=1
sysctl -w net.ipv4.conf.all.arp_ignore=1
Step 2:
reboot
Step 3:
I created a .sh script, based on the original/default output from ip route:
#!/bin/bash
# crontab -e
# @reboot sleep 120; /home/mona/ip_route_rules_for_separate_eth0_eth1.sh
if grep -Fxq '252 ispa' "/etc/iproute2/rt_tables"; then
echo ""
else
echo '252 ispa' >> "/etc/iproute2/rt_tables"
fi
if grep -Fxq '251 ispb' "/etc/iproute2/rt_tables"; then
echo ""
else
echo '251 ispb' >> "/etc/iproute2/rt_tables"
fi
#Eth1:
ip rule add from 192.168.1.156 table ispa prio 1
ip route add 192.168.1.0/24 dev eth1 proto kernel scope link src 192.168.1.156 table ispa
ip route add 192.168.1.1 dev eth1 proto dhcp scope link src 192.168.1.156 metric 100 table ispa
ip route add default via 192.168.1.1 dev eth1 proto dhcp src 192.168.1.156 metric 100 table ispa
#Eth0:
ip rule add from 192.168.1.155 table ispb prio 1
ip route add 192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.155 table ispb
ip route add 192.168.1.1 dev eth0 proto dhcp scope link src 192.168.1.155 metric 100 table ispb
ip route add default via 192.168.1.1 dev eth0 proto dhcp src 192.168.1.155 metric 100 table ispb
I'm using the croon job on reboot, but this is probably wrong, since interface restarts wouldn't apply rules.
Does anyone know how can I rewrite these commands to be executed by netplan?
