Can only bring up one of two interfaces
Solution 1
I found the solution. There were two gateways defined in /etc/network/interfaces while you simple can't have more then one gateway. It makes no sense.
A gateway is an IP you send ALL traffic to. If you would have two, your routing table would have a double entry for dest 0.0.0.0 and the system can't handle this. The double route is what causes the RTNETLINK answer "File exists", meaning there is already a route for 0.0.0.0.
I've commented out one of the gateways and now I can ifup both eth0 and eth1.
tl;dr delete gateway entries until you've got only one left.
Solution 2
From this link i learned a lot it helped me fixing the error.
Just add the following line to your /etc/network/interfaces below your eth0 config:
pre-up ip addr del 192.168.1.254/24 dev eth0 2> /dev/null || true
It's not the most beautiful solution but ad least it works. Credits go to the owner of grapsus.net and google.
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mstaessen
Updated on September 18, 2022Comments
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mstaessen almost 2 years
I'm having a bizarre issue with my HP Proliant DL 360 G4p server. It has two gigabit ethernet interfaces but I can bring up only one of them. This is starting to freak me out and that's why I turned here. I'm running the x64 ubuntu 11.10 server edition.
lshw -c network shows that the second interface is disabled. I have no idea why ans how to enable it.
$ sudo lshw -c network *-network:0 description: Ethernet interface product: NetXtreme BCM5704 Gigabit Ethernet vendor: Broadcom Corporation physical id: 2 bus info: pci@0000:02:02.0 logical name: eth0 version: 10 serial: 00:18:71:e3:6d:26 size: 100Mbit/s capacity: 1Gbit/s width: 64 bits clock: 66MHz capabilities: pcix pm vpd msi bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=tg3 driverversion=3.119 duplex=full firmware=5704-v3.27b, ASFIPMIc v2.36 ip=10.48.8.x latency=64 link=yes mingnt=64 multicast=yes port=twisted pair speed=100Mbit/s resources: irq:25 memory:fdf70000-fdf7ffff *-network:1 DISABLED description: Ethernet interface product: NetXtreme BCM5704 Gigabit Ethernet vendor: Broadcom Corporation physical id: 2.1 bus info: pci@0000:02:02.1 logical name: eth1 version: 10 serial: 00:18:71:e3:6d:25 capacity: 1Gbit/s width: 64 bits clock: 66MHz capabilities: pcix pm vpd msi bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=tg3 driverversion=3.119 firmware=5704-v3.27b latency=64 link=no mingnt=64 multicast=yes port=twisted pair resources: irq:26 memory:fdf60000-fdf6ffff
If I try to ifup eth1, then I get
$ sudo ifup eth1 Ignoring unknown interface eth1=eth1.
I figured that's what happens when there is no eth1 listed in /etc/network/interfaces. But when I add the configuration for eth1, I still can't ifup.
$ sudo ifup eth1 RTNETLINK answers: File exists Failed to bring up eth1. I've also tried ifconfig eth1 up but without any result.
For clarity, I have added a masked version of /etc/network/interfaces. I don't think it is the cause of the problem though.
$ cat /etc/network/interfaces # This file describes the network interfaces available on your system # and how to activate them. For more information, see interfaces(5). # The loopback network interface auto lo iface lo inet loopback # The primary network interface auto eth0 iface eth0 inet static address 10.48.8.x netmask 255.255.255.y network 10.48.8.z broadcast 10.48.8.t gateway 10.48.8.u auto eth1 iface eth1 inet static address 193.190.253.x netmask 255.255.255.y network 193.190.253.z broadcast 193.190.253.t gateway 193.190.253.u
I really need some help fixing this. It's driving me crazy. Thanks.
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Allan Jude over 12 yearsCan you provide the contents of both your /etc/network/interfaces eth0 and eth1
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Kyle Brandt over 12 yearsIn the past I made the mistake of copying an interface config but not changing the MAC address with CentOS, not sure if that applies here, would need to see
/etc/network/interfaces
as Allan said -
mstaessen over 12 yearsdone. Don't think it's very relevant though. Seems correct to me :)
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mstaessen over 12 yearsCables are perfectly fine. I can bring up either eth1 or eth0 but never both. Both NICs have already worked so that won't probably be it.
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mstaessen over 12 yearsThe ilo port is not visible to the operating system, so no. There are three ethernet cables plugged in. All working fine. The problem is the NIC itself. It won't allow me to activate the two interfaces simultaneously.
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SimonJGreen over 12 yearsJust FYI, you can have multiple gateways, just not 2 DEFAULT gateways. That's exactly what the routing table is for, to define the gateway for different destinations. A default gateway is simply the final match in the list.
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Lisandro almost 12 yearsLook out! On Ubuntu 12.04 (The only one I tested this in) a full reboot is required if you miss configure the second NIC.
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mstaessen almost 12 yearsDon't think I had that issue.
/etc/init.d/networking restart
works fine -
Michael over 10 yearsI add
post-up ip route delete default via 10.0.0.1
after the iface declaration in/etc/network/interfaces
, changing 10.0.0.1 to the IP of the default gateway you want to delete.