[SOLVED] No network communication in some Linux distros

[JuanMacClane]

Hi guys,

I have some weird issue with proxmox 6 & 7 when using some Linux distros in my VM.

The network card is detected correctly and i can configure correctly the ip but there is no communication outside, when i try to ping to the gateway or google, i see a message network unreachable.

This happens for example with Clonezilla and also an old CentOS version.
With same VM running a Live Linux Mint ISO i can configure and ping the internet without any problem.

Not sure if its related because the network card is detected as eth0 in clonezilla and old centos, and Linux Mint detects as ens18 ... i tried to change the name but result is the same.

Also tried to configure the card as Intel , VirtIO, Realtek... and see no difference

 

[oguz]

hi,

Not sure if its related because the network card is detected as eth0 in clonezilla and old centos, and Linux Mint detects as ens18 ... i tried to change the name but result is the same.

that shouldn't matter afaik.

The network card is detected correctly and i can configure correctly the ip but there is no communication outside, when i try to ping to the gateway or google, i see a message network unreachable.

This happens for example with Clonezilla and also an old CentOS version.

do you have a DHCP server? or are you using static IP addresses?

I have some weird issue with proxmox 6 & 7 when using some Linux distros in my VM.

is PVE running on bare metal? if you're using another hypervisor on top you might have to enable mac spoofing / promiscuous mode or so..

Also tried to configure the card as Intel , VirtIO, Realtek... and see no difference

you can post:
* the VM configurations (working & non-working, use qm config VMID command and replace VMID with yours)
* routing table inside the VMs ip a && ip r
* node network configuration cat /etc/network/interfaces

 

[JuanMacClane]

Hi , first of all , thanks for your quick reply and sorry for the delay, i ve been quite busy.

Here is all requested info, notice i changed the ips and some other for security.


VM CONFIGURATION (Note its the same machine, but running a liveISO for Mint)
/usr/sbin/qm config 101

boot: order=ide2;sata0;net0
cores: 2
ide2: local:iso/linuxmint-20.3-cinnamon-64bit.iso,media=cdrom,size=2198880K
memory: 4096
meta: creation-qemu=6.1.0,ctime=1644244588
name: mymachine
net0: rtl8139=XX:XX:XX:XX:XX:XX,bridge=vmbr0,firewall=1
numa: 0
ostype: l26
sata0: local:101/vm-101-disk-0.qcow2,size=80G,ssd=1
smbios1: uuid=x-x-x-x-x
sockets: 1
vmgenid: XX-XX-XX


-- LINUX MINT CONFIG (WORKING) --


mint@mint:~$ ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: ens18: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
link/ether 00:50:XX:XX:XX:XX brd ff:ff:ff:ff:ff:ff
inet 195.XXX.XXX.XXX/32 scope global noprefixroute ens18
valid_lft forever preferred_lft forever
inet6 2001:bc8:xxxxx:x:xxxx:xxxx:fe01:f9f9/64 scope global dynamic mngtmpaddr noprefixroute
valid_lft 2591996sec preferred_lft 604796sec
inet6 fe80::aaa:aaaa:aaaa:f9f9/64 scope link noprefixroute
valid_lft forever preferred_lft forever
mint@mint:~$ ip r
default via 62.yyy.y.y dev ens18 proto static metric 100
62.yyy.y.y dev ens18 proto static scope link metric 20100
169.254.0.0/16 dev ens18 scope link metric 1000


mint@mint:~$ cat /etc/interfaces


# interfaces(5) file used by ifup(8) and ifdown(8)
# Include files from /etc/network/interfaces.d:
source-directory /etc/network/interfaces.d


(interfaces.d is empty)



-- CENTOS CONFIG (NOT WORKING) --

ip a

1: lo: <LOOPBACK,UP, LOWER_UP> mtu 16436 qdisc noqueue
link/loopback 00:00:0:00:00:00 brd 00:00:00:00:00
inet 127.0.0.1/8 scope host lo
inet 6 ::1/128 scope host
valid_lft forever preferred_lft forever

2: eth0 <BROADCAST, MULTICAST, UP, LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
llink/ether 00:50:XX:XX:XX:XX brd ff:ff:ff:ff:ff:ff
inet 195.XXX.XXX.XXX/32 brd 195.XXX.XXX.XXX scope global eth0
inet6 2001:bc8:xxxx:x:xxx:xxxx:fe01:f9f9/64 scope global dynamic
valid_lft 2591998sec preferred_lft 604798
inet6 fe80::aaa:aaaa:aaaa:f9f9/64 scope link
valid_lft forever preferred_lft forever
3: sit0: <NOARP> mtu 1480 qdisc noop
link/sit 0.0.0.0 brd 0.0.0.0


ip r

169.254.0.0/16 dev eth0 scope link

no /etc/network/interfaces (cat /etc/sysconfig/network-scripts/ifcfg-eth0)
#Realtek Semiconductor Co. Ltd RTL-8139/8139C/8139C+
DEVICE=eth0
BOOTPROTO=none
HWADDR=00:50:XX:XX:XX:XX
ONBOOT=yes
NETMASK=255.255.255.255
IPADDR=195.XXX.XX.XXX
GATEWAY=62.yyy.y.y
TYPE=Ethernet


Then when i ping to 8.8.8.8 : Network unreachable
pign to gateway 62....


if i try to add a route i receive SIOCADDRT :Network is unreachable

 

[oguz]

ip r

169.254.0.0/16 dev eth0 scope link

your route looks incorrect, you have an IP address starting with 195 according to your output

 

[JuanMacClane]

your route looks incorrect, you have an IP address starting with 195 according to your output

yes , but when i try to add a new route i receive:
SIOCADDRT :Network is unreachable

 

[JuanMacClane]

Hi, sorry for the long time,
yes it was caused because the routes in the OS, not sure why some OS dont let me use some routes and other allows it.
Also i tested standard gateway 195.xxx.xxx.1 and worked. Dont know why in the provider's documents is not that option

Thanks for your help and patience
(you can close thread as solved)