Can't ping a node in my cluster but was able to join the cluster just fine. No other network access

warloxian

Member
Jun 26, 2021
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I am still an amateur at Linux networking, but I am learning. I have 6 nodes in my cluster. All have Proxmox 8. 1 node isn't showing up on my router or switches. The web interface works fine and I am able to log into it. I am unable to ping anything from the faulty node, nothing inside or outside. I was able to add this node to my cluster.
Basically, this node is invisible to everything on my network and I have no access to wan. I am able to ssh into this node from any device on my network and I am able to ssh into every device on my network from this node. Even though i am unable to ping from or to this node from anywhere on my network , I am able to access the web gui and was able to join the cluster. The only other mystery , to me, is that when i run nmap from this node it picks up every device on my network and shows my all open ports. This is so weird and I haven't been able to find an answer after a couple weeks of searching. I have looked at
ip a
Code:
root@dl380G7:~# 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: enp3s0f0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq master vmbr0 state UP group default qlen 1000
    link/ether e4:11:5b:bb:0a:5c brd ff:ff:ff:ff:ff:ff
3: enp3s0f1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN group default qlen 1000
    link/ether e4:11:5b:bb:0a:5e brd ff:ff:ff:ff:ff:ff
4: enp4s0f0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether e4:11:5b:bb:0a:60 brd ff:ff:ff:ff:ff:ff
5: enp4s0f1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether e4:11:5b:bb:0a:62 brd ff:ff:ff:ff:ff:ff
6: vmbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether e4:11:5b:bb:0a:5c brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.85/24 scope global vmbr0
       valid_lft forever preferred_lft forever
    inet6 fe80::e611:5bff:febb:a5c/64 scope link
       valid_lft forever preferred_lft forever
root@dl380G7:~#

cat /etc/network/interfaces
Code:
cat /etc/network/interfaces
# network interface settings; autogenerated
# Please do NOT modify this file directly, unless you know what
# you're doing.
#
# If you want to manage parts of the network configuration manually,
# please utilize the 'source' or 'source-directory' directives to do
# so.
# PVE will preserve these directives, but will NOT read its network
# configuration from sourced files, so do not attempt to move any of
# the PVE managed interfaces into external files!

auto lo
iface lo inet loopback

auto enp3s0f1
iface enp3s0f1 inet manual

iface enp3s0f0 inet manual

iface enp4s0f0 inet manual

iface enp4s0f1 inet manual

auto vmbr0
iface vmbr0 inet static
        address 192.168.0.85/24
        gateway 192.168.0.1
        bridge-ports enp3s0f0
        bridge-stp off
        bridge-fd 0

This is a very basic lab that has absolutely nothing important. I have 6 old servers that I use to practice penetration testing. But I know I can never be a good pen tester unless I understand how networking works COMPLETELY!!! Please help me to become a professional and I will reciprocate once I have answers.

Thank you for spending some of your valuable time trying to assist this wanna be ethical hacker
 
Last edited:
Have you stored your DNS correctly in resolv.conf? What error message do you get and which commands exactly don't work? Even if you are a beginner, you should know that we need food here, otherwise the help won't work.
 
I have tailscale installed on 4 of my other nodes, but I have 1 node that doesn't have tailscale yet and with the same resolv.conf and I have no problems with it
ping any internal or external address are always 100% packet loss
Try to ping this node and I get 100% packet loss
Web GUI is accessible and works fine
I can ssh into or out of the faulty node just fine, I was able to join the cluster, was slow in joining but it joined and is accessible through the cluster
I look at connected devices on my router and it's not on the list, I look at connected devices on my switch and it's not there, but if I run nmap from the faulty node it picks up every single device on my network and if I run nmap 192.168.0.85 nmap will find and scan this node just fine?
 
nmap scan from the troubled node , of the troubled node (192.168.0.85)
Code:
nmap 192.168.0.85
Starting Nmap 7.93 ( https://nmap.org ) at 2023-11-23 17:43 MST
Nmap scan report for dl380G7.lan (192.168.0.85)
Host is up (0.000011s latency).
Not shown: 997 closed tcp ports (reset)
PORT     STATE SERVICE
22/tcp   open  ssh
111/tcp  open  rpcbind
3128/tcp open  squid-http

Nmap done: 1 IP address (1 host up) scanned in 0.11 seconds
 
No one else? I know it's the holiday season and wish you all blessings and a prosperous New year.If I am slow to respond it's only because of the holidays
 
cat resolv.conf
search lan
nameserver 8.8.8.8
Remove the line "search lan", unless you actually have this domain running functionally on your network.
What error message do you get and which commands exactly don't work? Even if you are a beginner, you should know that we need food here, otherwise the help won't work.
Please read again carefully my quote. You've repeatedly said that X doesn't work and Y doesn't work, but you're unable to attach a log excerpt or take a screenshot. It's hard to understand what you've built if you don't give out any information or error messages.
I know it's the holiday season
No, not in Germany - that's where I live. So maybe it's just a matter of the time zone you're in. For me it's currently 8:10 p.m.
nmap scan from the troubled node , of the troubled node (192.168.0.85)
What do you see in the browser when you access https://192.168.0.85:8006 ?
 
To anyone that tried to make sense of my problem, I appreciate tour time. After a number of HOURS i figured my problem out. It was an issue with my router. I had previously bound the mac and ip address of this node, to an entirely different machine. Once I cleared it out all problems were resolved.
 

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