[SOLVED] Unable to access or ping Proxmox

[hhharsha36]

I am running the latest version of Proxmox (8.2) which was working fine for about a week. I created a new VM with network in bridge mode and installed Alpine linux on it. Post install, I rebooted the VM and I was unable to access UI Proxmox. I tried pinging the Proxmox IP and it returned Destination host Unreachable error upon ping.

I tried to identify the issue manually by connecting a monitor to it and found that I am unable to ping my router's IP which is also the default gateway (192.168.50.1) from proxmox shell. I tried suggestions from other answers on the forum with no luck.

Below are the screenshots of various inforation related to network configuration I was able to fetch. Apologies for the picture instead of code snippet since I had to rely on output from my monitor.

 

[Hannes Laimer]

Hey,

any idea how enp2s0 ended up with two IPs? It should have none, since vmbr0 has an IP. Could you run

ip addr flush dev enp2s0

to remove the IP addresses assigned to the interface directly, and

ifreload -av

to reload everything. Does ifreload complain about anything?

 

[hhharsha36]

Thank you for your response.

Initially enp2s0 had only one ip (192.168.50.15. I thought it might be an ip issue and attempted to add additional ip (192.168.50.20) using commands:

ip addr add 192.168.50.20/24 dev enp2s0
ip link set enp2s0 up

ip addr flush dev enp2s0

I tried this commend and below are the contents of ip route now, and its the same as what it used to be before I ran the ip addr add command:

root@proxmox:"# ip route
default via 192.168.50.1 dev vmbr0 proto kernel onlink
192.168.50.0/24 dev vmbr® proto kernel scope link src 192.168.50.15

Unfortunately I am still facing the issue. Even tried rebooting the Proxmox cluster.

Below are the contents of ifreload -av command:

info: requesting link dump
info: requesting address dump
info: requesting netconf dump
info: loading builtin modules from ['/usr/share/i fupdoun2/addons']
info: module openswitch not loaded (module init failed: no /us/bin/ovs-vsctl found)
info: module openswitch_port not loaded (module init failed: no /us/bin/ovs-vsctl found)
info: module ppp not loaded (module init failed: no /us/bin/pon found)
info: module batman_adv not loaded (module init failed: no /usr/sbin/batctl found)
info: executing /sbin/sysctl net.bridge.bridge-allow-multiple-vlans
info: module mstpctl not loaded (module init failed: no /sbin/mstpctl found)
info: executing /bin/ip rule show
info: executing /bin/ip -6 rule shou
info: address: using default mtu 1500
info: address: max_mtu undefined
info: executing /sbin/sysctl net.ipv6.conf.all.accept_ra
info: executing /sbin/sysctl net.ipv5.conf.all.autoconf
info: executing /usr/sbin/ip vrf id
info: mgnt vrf_context = False
info: executing /bin/ip addr help info: address metric support: 0K
info: module ppp not loaded (module init failed: no /us/bin/pon found)
info: module mstpctl not loaded (module init failed: no /sbin/mstpctl found)
info: module batman_adv not loaded (module init failed: no /usr/sbin/batctl found)
info: module openswitch_port not loaded (module init failed: no /us/bin/ovs-vscti found)
info: module openswitch not loaded (module init failed: no /us/bin/ovs-vsctl found)
info: looking for user scripts under /etc/network
info: loading scripts under /etc/network/if-pre-up.d...
info: loading scripts under /etc/network/if-up.d...
info: loading scripts under /etc/network/if-post-up.d...
info: loading scripts under /etc/network/if-pre-down.d...
info: loading scripts under /etc/network/if-down.d
info: loading scripts under /etc/network/if-post-down.d...
info: 'link_master_slave' is set. slave admin state change will be delayed till the masters admin state change.
info: using mgmt iface default prefix eth
info: processing interfaces file /etc/network/interfaces
info: no interfaces to down ..
info: reload: scheduling up on interfaces: ['10", 'vmbra']
info: lo: running ops ...
info: executing /sbin/sysctl net.mpls.conf.lo.input=0
info: executing /etc/network/if-up.d/postfix
info: executing /etc/network/if-up.d/chrony
info: enp20: running ops ...
info: vmbrD: applying bridge port configuration: L'enp2s0']
info: vrf: syncing table map to /etc/iproute2/rt_tables.d/ifupdown2_vrf_map.conf
info: vrf: dumping iproute2_vrf_map info: ()
info: executing /sbin/sysctl net.mpls.conf.enp2s0.input=0
info: executing /etc/network/if-up.d/postfix
info: executing /etc/network/if-up.d/chrony
info: vmbr0: running ops ...
info: vmbr0: bridge already exists
info: vmbr0: applying bridge settings
info: vmbr0: reset bridge-hashel to default: 4
info: reading '/sys/class/net/vmbr/bridge/stp_state*
info: vmbr0: netlink: ip link set dev vmbrO type bridge (with attributes)
info: vmbr0: port fupr100p0 will stay enslaved as it matches with bridge-ports-condone-regex
info: vmbr0: port fupr101p0 will stay enslaved as it matches with bridge-ports-condone-regex
info: vmbr0: port enp2s0: already processed
info: vmbr0: applying bridge configuration specific to ports
info: vmbr0: processing bridge config for port enp2st
info: bridge mac is already inherited from enp2sO
info: executing /sbin/sysctl net.mpls.conf.vmbr0.input=0
info: writing '0' to file /proc/sys/net/ipv4/conf/vmbrD/arp_accept
info: executing /bin/ip route replace default via 192.168.50.1 proto kernel dev vmbrO onlink
info: executing /etc/network/if-up.d/postfix
info: executing /etc/network/if-up.d/chrony
info: exit status 0

 

[Hannes Laimer]

Hey,

what is the output of ip a after

ip addr flush dev enp2s0
ifreload -av

?

 

[hhharsha36]

Hey,

what is the output of ip a after

root@proxmox: *# 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 1o
   valid_Ift forever preferred_Ift forever inet6 ::1/128 scope host noprefixroute valid_lft forever preferred_Ift forever
2. enp2s: ‹BROADCAST, MULTICAST,UP,LOWER UP> mtu 1500 gdisc pfifo_fast master vmbr® state UP group default qlen 1000 link/ether 58:47:ca: 77:89:4b brd ff:ff:ff:ff:ff:ff
3. enp3s: <BROADCAST, MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000 link/ether 58:47:ca: 77:89:4a brd ff:ff:ff:ff:ff:ff
4. wIps0: ‹BROADCAST, MULTICAST> mtu 1500 disc noop state DOWN group default qlen 1000 link/ether dc: 97:ba: 40: fc: 18 brd ff:ff:ff:ff:ff:ff
5. vmbrO: «BROADCAST, MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qen 1000 link/ether 58:47:ca: 77:89:4b brd ff:ff:ff:ff:ff:ff inet 192.168.50.15/24 scope global vmbrO valid_lft forever preferred_lft forever inet6 fe80: :5a47:caff: fe77:894b/64 scope link valid_lft forever preferred_lft forever
6. tap10010: <BROADCAST, MULTICAST, PROMISC,UP LOWER_UP> mtu 1500 qdisc pfifo_fast master fubr 10010 state UNKNOWN group default qlen 1000 link/ether 9e:01:db: 45:09:be brd ff:ff:ff:ff:ff:ff
7. fubr 10010: ‹BROADCAST, MULTICAST, UP, LOWER UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether 56:8a:5f:c:5d:b7 brd ff:ff:ff:ff:ff:ff
8. fupr 100p0@fuln10010: ‹BROADCAST, MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master vmbr® state UP group default qlen 1000 link/ether 8a:d6:4e: 1a: 48:4a brd ff:ff:ff:ff:ff:ff
   fuln100100fupr 100pD: <BROADCAST, MULTICAST, UP, LOWER_UP> mtu 1500 gdisc noqueue master fubr10010 state UP group default qlen 1000 link/ether 56:8a:5f:Bc:5d:b7 brd ff:ff:ff:ff:ff:ff
9. tap10110: «BROADCAST, MULTICAST, PROMISC,UP, LOWER_UP> mtu 1500 disc pfifo_fast master fubr10110 state UNKNOWN group default qlen 1000 link/ether 36:df:9b:2d:13:6d brd ff:ff:ff:ff:ff:ff
10. fubr 10110: «BROADCAST, MULTICAST, UP, LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link/ether Da:09:a1:06:f9:bl brd ff:ff:ff:ff:ff:ff
11. fupr101p00fwln10110: <BROADCAST, MULTICAST, UP, LOWER_UP> mtu 1500 qdisc noqueue master vmbr0 state UP group default qlen 1000 link/ether Ba:3d: d6:83:b2:bf brd ff:ff:ff:ff:ff:ff
12. fwln101100fupr101p0: ‹BROADCAST, MULTICAST, UP, LOWER_UP> mtu 1500 qdisc noqueue master fubr10110 state UP group default qlen 1000 link/ether Da:09:a1:06:9:b1 brd ff:ff:ff:ff:ff:ff

 

[Hannes Laimer]

The picture does not match the text, which is the state right after the two commands? enp2s0 should not have an IP assigned to it, only vmbr0 should have one.

 

[hhharsha36]

Hey,

what is the output of ip a after

My NUC and Proxmox VMs are assigned an IP address from my router

 

[hhharsha36]

The picture does not match the text, which is the state right after the two commands? enp2s0 should not have an IP assigned to it, only vmbr0 should have one.

The picture is the correct one, I used a third party software to convert image to text for convenience. Sorry

I took the picture just now after ip addr flush dev enp2s0 operation.

 

[Hannes Laimer]

Is the NUC where PVE runs on? PVE does not get its IP from DHCP, it is specified statically in /etc/network/interfaces. Did you do any network configuration aside from /etc/network/interfaces?

 

[hhharsha36]

Is the NUC where PVE runs on? PVE does not get its IP from DHCP, it is specified statically in /etc/network/interfaces. Did you do any network configuration aside from /etc/network/interfaces?

Yes, the NUC is where PVE runs on. It is two ethernet ports and only one is connected to router. The other one is left as is.

I did not perform any additional network configuration since the initial setup other than assigning additional IP (192.168.50.20) which apparently made things much more worse.

 

[Hannes Laimer]

after

ip addr flush dev enp2s0
ifreload -av

enp2s0 still has two IPs assigned to it? If that's the case, I don't see how that is possible since PVE does not do any DHCP, so it does not matter what is set on the router. Could you also remove the entry for the PVE on your router.

 

[hhharsha36]

after

ip addr flush dev enp2s0
ifreload -av

enp2s0 still has two IPs assigned to it? If that's the case, I don't see how that is possible since PVE does not do any DHCP, so it does not matter what is set on the router. Could you also remove the entry for the PVE on your router.

Thank you very much for your patience and guidance @Hannes Laimer

Here is what I have done.
1. Removed the static configurations on my router
2. Run the ip addr flush dev enp2s0 commands again
3. Reboot the PVE

Which seems to have fixed the enp2s0 issue you pointed, but unfortunately it is still unable to ping the default gateway

 

[Hannes Laimer]

So

ping 192.168.50.1

fails? Just to be sure, your router is 192.168.50.1, right? Can you ping any other devices on 192.168.50.0/24?

 

[hhharsha36]

So

ping 192.168.50.1

fails? Just to be sure, your router is 192.168.50.1, right? Can you ping any other devices on 192.168.50.0/24?

I am able to ping all other devices on my network except for my Router (192.168.50.1)




That being said, I am unable to ping PVE from other devices in my network

ping 192.168.50.15     
PING 192.168.50.15 (192.168.50.15): 56 data bytes
Request timeout for icmp_seq 0
Request timeout for icmp_seq 1
^C
--- 192.168.50.15 ping statistics ---
3 packets transmitted, 0 packets received, 100.0% packet loss

 

[Hannes Laimer]

Do you have a firewall configured either on PVE, or your router?

 

[hhharsha36]

No, I have disabled firewall on my router and don't recall setting up firewall on PVE



I tried uninstalling and reinstalling PVE again from scratch on my NUC and everything seemed to working fine at first. I created a VM and installed Debian linux on it. Post install, I shutdown the VM and tried to manually set the MAC address which is the same as the existing one assigned to the VM by PVE and that was when it broke again.

Same problem as I faced previously, where the PVE is assigned an IP by the router, but unable to ping the default gateway. I am able to ping other hosts on the network from PVE but the other way around. Very weird.

 

[hhharsha36]

I managed to solve the issue. If the PVE is connected to an ASUS router, be sure to disable LAG (Link Aggregation) option under LAN settings. Disabling it solved the issue for me.