[SOLVED] No connection on fresh installation

[Syrio]

Hi,

I recently installed proxmox but can't get the ethernet connection to work (can't ping anything). Proxmox is new to me and thus it's possible that I've missed something obvious. I've read through a multitude of posts and tried various things that have worked for others. I've also tried to connect to different routers, testing with different cables but that didn't solve the issue. I've included some information that has been requested in other posts. Hopefully you guys might have some suggestions.

pveversion -v

Spoiler

proxmox-ve: 5.4-1 (running kernel: 4.15.18-12-pve)
pve-manager: 5.4-3 (running version: 5.4-3/0a6eaa62)
pve-kernel-4.15: 5.3-3
pve-kernel-4.15.18-12-pve: 4.15.18-35
corosync: 2.4.4-pve1
criu: 2.11.1-1~bpo90
glusterfs-client: 3.8.8-1
ksm-control-daemon: 1.2-2
libjs-extjs: 6.0.1-2
libpve-access-control: 5.1-8
libpve-apiclient-perl: 2.0-5
libpve-common-perl: 5.0-50
libpve-guest-common-perl: 2.0-20
libpve-http-server-perl: 2.0-13
libpve-storage-perl: 5.0-41
libqb0: 1.0.3-1~bpo9
lvm2: 2.02.168-pve6
lxc-pve: 3.1.0-3
lxcfs: 3.0.3-pve1
novnc-pve: 1.0.0-3
proxmox-widget-toolkit: 1.0-25
pve-cluster: 5.0-36
pve-container: 2.0-37
pve-docs: 5.4-2
pve-edk2-firmware: 1.20190312-1
pve-firewall: 3.0-19
pve-firmware: 2.0-6
pve-ha-manager: 2.0-9
pve-i18n: 1.1-4
pve-libspice-server1: 0.14.1-2
pve-qemu-kvm: 2.12.1-3
pve-xtermjs: 3.12.0-1
qemu-server: 5.0-50
smartmontools: 6.5+svn4324-1
spiceterm: 3.0-5
vncterm: 1.5-3
zfsutils-linux: 0.7.13-pve1~bpo2[/B]

/etc/network/interfaces

Spoiler

auto lo
iface lo inet loopback

iface enp7s1 inet manual

auto vmbr0
iface vmbr0 inet static
    address 192.168.1.50
    netmask 255.255.255.0
    gateway 192.168.1.1
    bridge_ports enp7s1
    bridge_stp off
    bridge_fd 0

lspci -v

Spoiler

07:01.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8110SC/8169SC Gigabit Ethernet (rev 10)
   Subsystem: ASUSTeK Computer Inc. RTL-8110SC/8169SC Gigabit Ethernet
   Flags: bus master, 66MHz, medium devsel, latency 64, IRQ 19
   I/O ports at e800 [size=256]
   Memory at fbeffc00 (32-bit, non-prefetchable) [size=256]
   Expansion ROM at fbec0000 [disabled] [size=128K]
   Capabilities: [dc] Power Management version 2
   Capabilities: [60] Vital Product Data
   Kernel driver in use: r8169
   Kernel modules: r8169

dmesg | grep -E "enp7s1|eth0"

Spoiler

[    1.066199] r8169 0000:07:01.0 eth0: RTL8169sc/8110sc at 0x        (ptrval), bc:ae:c5:19:eb:d1, XID 18000000 IRQ 19
[    1.066201] r8169 0000:07:01.0 eth0: jumbo features [frames: 7152 bytes, tx checksumming: ok]
[    1.108808] r8169 0000:07:01.0 enp7s1: renamed from eth0
[   10.638316] vmbr0: port 1(enp7s1) entered blocking state
[   10.638319] vmbr0: port 1(enp7s1) entered disabled state
[   10.638399] device enp7s1 entered promiscuous mode
[   10.680076] r8169 0000:07:01.0 enp7s1: link down
[   10.680089] r8169 0000:07:01.0 enp7s1: link down

ethtool enp7s1

Spoiler

Settings for enp7s1:
   Supported ports: [ TP MII ]
   Supported link modes:   10baseT/Half 10baseT/Full
                           100baseT/Half 100baseT/Full
                           1000baseT/Half 1000baseT/Full
   Supported pause frame use: No
   Supports auto-negotiation: Yes
   Advertised link modes:  10baseT/Half 10baseT/Full
                           100baseT/Half 100baseT/Full
                           1000baseT/Half 1000baseT/Full
   Advertised pause frame use: Symmetric Receive-only
   Advertised auto-negotiation: Yes
   Speed: 10Mb/s
   Duplex: Half
   Port: MII
   PHYAD: 0
   Transceiver: internal
   Auto-negotiation: on
   Supports Wake-on: pumbg
   Wake-on: g
   Current message level: 0x00000033 (51)
                  drv probe ifdown ifup
   Link detected: no[/B]

 

[wolfgang]

Hi,

the configuration looks ok in terms of syntax.
But your link is down.

can you send the output of

ip r
ip -d a

 

[Syrio]

Sure thing

ip r

Spoiler

default via 192.168.1.1 dev vmbr0 onlink linkdown
192.168.1.0/24 dev vmbr0 proto kernel scope link src 192.168.1.50 linkdown

ip -d a

Spoiler

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 promiscuity 0 numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535
    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: enp7s1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast master vmbr0 state DOWN group default qlen 1000
    link/ether bc:ae:c5:19:eb:d1 brd ff:ff:ff:ff:ff:ff promiscuity 1
    bridge_slave state disabled priority 32 cost 100 hairpin off guard off root_block off fastleave off learning on flood on port_id 0x8001 port_no 0x1 designated_port 32769 designated_cost 0 designated_bridge 8000.bc:ae:c5:19:eb:d1 designated_root 8000.bc:ae:c5:19:eb:d1 hold_timer    0.00 message_age_timer    0.00 forward_delay_timer    0.00 topology_change_ack 0 config_pending 0 proxy_arp off proxy_arp_wifi off mcast_router 1 mcast_fast_leave off mcast_flood on neigh_suppress off group_fwd_mask 0x0 group_fwd_mask_str 0x0 vlan_tunnel off numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535
3: vmbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether bc:ae:c5:19:eb:d1 brd ff:ff:ff:ff:ff:ff promiscuity 0
    bridge forward_delay 0 hello_time 200 max_age 2000 ageing_time 30000 stp_state 0 priority 32768 vlan_filtering 0 vlan_protocol 802.1Q bridge_id 8000.bc:ae:c5:19:eb:d1 designated_root 8000.bc:ae:c5:19:eb:d1 root_port 0 root_path_cost 0 topology_change 0 topology_change_detected 0 hello_timer    0.00 tcn_timer    0.00 topology_change_timer    0.00 gc_timer  210.41 vlan_default_pvid 1 vlan_stats_enabled 0 group_fwd_mask 0 group_address 01:80:c2:00:00:00 mcast_snooping 1 mcast_router 1 mcast_query_use_ifaddr 0 mcast_querier 0 mcast_hash_elasticity 4 mcast_hash_max 512 mcast_last_member_count 2 mcast_startup_query_count 2 mcast_last_member_interval 100 mcast_membership_interval 26000 mcast_querier_interval 25500 mcast_query_interval 12500 mcast_query_response_interval 1000 mcast_startup_query_interval 3124 mcast_stats_enabled 0 mcast_igmp_version 2 mcast_mld_version 1 nf_call_iptables 0 nf_call_ip6tables 0 nf_call_arptables 0 numtxqueues 1 numrxqueues 1 gso_max_size 65536 gso_max_segs 65535
    inet 192.168.1.50/24 brd 192.168.1.255 scope global vmbr0
       valid_lft forever preferred_lft forever

 

[wolfgang]

It looks like your cable is not plugged or the switch port is down?
Check the cable.

 

[Syrio]

Thought so at first too, but the same cable works just fine on another machine. It also worked without any problems before I installed proxmox (had Arch running). Anyway, I tried with a couple of other cables but the problem remains. Any other suggestions?

 

[wolfgang]

What is the output of

ifdown vmbr0 && ifup -d -v vmbr0

 

[Syrio]

-d wasn't an available option but here is the output using only the verbose flag:

Spoiler

ifup: configuring interface vmbr0=vmbr0 (inet)
/bin/run-parts --exit-on-error --verbose /etc/network/if-pre-up.d
run-parts: executing /etc/network/if-pre-up.d/bridge

Waiting for vmbr0 to get ready (MAXWAIT is 2 seconds).
run-parts: executing /etc/network/if-pre-up.d/ethtool
run-parts: executing /etc/network/if-pre-up.d/ifenslave
+ [ inet = meta ]
+ IF_BOND_SLAVES=
+ [  ]
+ [  ]
+ [ -z  ]
+ exit
run-parts: executing /etc/network/if-pre-up.d/vlan
/bin/ip addr add 192.168.1.50/255.255.255.0 broadcast 192.168.1.255       dev vmbr0 label vmbr0
/bin/ip link set dev vmbr0   up
 /bin/ip route add default via 192.168.1.1  dev vmbr0 onlink
/bin/run-parts --exit-on-error --verbose /etc/network/if-up.d
run-parts: executing /etc/network/if-up.d/bridgevlan
run-parts: executing /etc/network/if-up.d/bridgevlanport
run-parts: executing /etc/network/if-up.d/ethtool
run-parts: executing /etc/network/if-up.d/ifenslave
+ [ inet = meta ]
+ [  ]
run-parts: executing /etc/network/if-up.d/mtu
run-parts: executing /etc/network/if-up.d/openssh-server
run-parts: executing /etc/network/if-up.d/postfix
run-parts: executing /etc/network/if-up.d/upstart

 

[timonych]

Thought so at first too, but the same cable works just fine on another machine. It also worked without any problems before I installed proxmox (had Arch running). Anyway, I tried with a couple of other cables but the problem remains. Any other suggestions?

I recommend You to boot with Ubuntu Live and check if link is up and Internet exists.

I think there is a problem with hardware / cable.

 

[Syrio]

I actually did that but had the same problem. Now I finally got it working though! Don't really know what the issue was but I did a reset in BIOS and enable check LAN cable on post after which I got a connection.. Anyway, thanks for taking the time guys!

 

[timonych]

did a reset in BIOS and enable check LAN

If Your BIOS is working in UEFI mode that Disabling Network stack in BIOS may cause such troubles.

 

[hardly]

I had this issue, and found that my Network Stack had been disabled in BIOS for some reason. Even then, rebooting with it enabled didn't work. Eventually, I tried a Ubunutu Live USB, which connected to the network. Rebooting back to Proxmox, and Proxmox was able to connect to the router, with zero config changes. Possibly the Ubuntu Live USB fixed something, though not sure.

 

[iGadget]

Just ran into this issue as well. r8169 works fine from an Ubuntu 20.04 live session, but when booting ProxMox, the link goes down (the light on my switch turns off as well). Rebooting into Ubuntu 20.04 - light goes back on, link is restored. But ProxMox just keeps knocking the card back down, even though it claims it's up and running (with a designated IP).
I checked the output of

ifdown vmbr0 && ifup -v vmbr0

and it's the same (apart from my IP) as #7.
I also checked my BIOS settings - it is working in UEFI mode but onboard LAN is enabled. I don't have any options like "Check LAN cable on post" as mentioned in #9.

Seems that whatever Proxmox is doing with the network settings (creating the vmbr0 interface?), r8169 doesn't like it.

Edit - I tested some more and when I do

ip link set enp6s0 up

I get this:

RTL8211DN Gigabit Ethernet r8169 0000:06:00.0 enp6s0: Link is Down
r8169 0000:06:00.0 enp6s0: Link is Up - 1Gbps/Full - flow control off
IPv6 ADDRCONF(NETDEV_CHANGE): enp6s0: link becomes ready

The link-light on my switch then turns on as well. However, the machine is still not reachable on the vmbr0 IP. Doing another

ifdown vmbr0 && ifup -v vmbr0

makes no difference.

Could it be enp6s0 is somehow not a part of vmbr0 (which I suppose it should be)?

How do I debug this?

 

[iGadget]

How do I debug this?

Found it!

Apparently, the network card was called "enp7s0" during installation. After first boot, the adapter suddenly became "enp6s0" but Proxmox was unaware of this and continued using "enp7s0". Which of course failed, since the card was no longer available under that name (so much for "predictable interface names", wasn't this the entire reason we so frantically had to get rid of good 'ol ethX?).

Manually editing

/etc/network/interfaces

and replacing all instances of "enp7s0" with "enp6s0" did the trick.
If anyone wishes me to do more research on *why* the interface name was changed, please point me in the right direction and I'll be happy to provide info.

 

[bvrulez]

How did you find out the card had a different name upon installation? I have a similar problem when installing with OVMF(UEFI) mode according to this guide. When I do it with default SeaBIOS I have a working network connection. It could also be related to the CPU beeing "host" or "Haswell-noTSX", though.