[BUG] I'm not receiving an ICMP reply when attempting to ping from the UE to the internet.

[Mouradnetworking]

Describe the issue

When attempting to ping Google's DNS (8.8.8.8) from the UE, only ICMP request packets are sent, but no ICMP reply is received. The following conditions have been checked:

Firewall (ufw): Inactive
iptables: No rules blocking ICMP traffic
IPv4 forwarding: 1

I'm using Packet Rusher for the radio part and Open5GS for the core part.

Screenshots

Architecture :
PRETTY_NAME="Ubuntu 22.04.4 LTS"
NAME="Ubuntu"
VERSION_ID="22.04"
VERSION="22.04.4 LTS (Jammy Jellyfish)"
VERSION_CODENAME=jammy

Pcap:
ping.zip

[linouxis9]

Hi @Mouradnetworking,

Nice to see you using PacketRusher. Have you made sure to setup NAT on the UPF's side as specified in Open5GS' documentation?
Did you try a ICMP ping towards the UPF too as well?

Thanks and cheers,
Valentin

[Mouradnetworking]

Hi Linou, thank you for your response.

I tried pinging the UPF (172.31.68.24), but it's not working.

Regarding NAT, I followed the Open5GS configuration using the commands:
""""
sudo iptables -t nat -A POSTROUTING -s 10.45.0.0/16 ! -o ogstun -j MASQUERADE
sudo ip6tables -t nat -A POSTROUTING -s 2001:db8:cafe::/48 ! -o ogstun -j MASQUERADE
""""
However, the issue persists.

$ip route

default via 172.31.64.1 dev ens5 proto dhcp src 172.31.68.24 metric 100
10.45.0.0/16 dev ogstun proto kernel scope link src 10.45.0.1
10.45.0.0/16 dev ogstun proto static
172.31.0.2 via 172.31.64.1 dev ens5 proto dhcp src 172.31.68.24 metric 100
172.31.64.0/20 dev ens5 proto kernel scope link src 172.31.68.24 metric 100
172.31.64.1 dev ens5 proto dhcp scope link src 172.31.68.24 metric 100

Best regards,

[Mouradnetworking]

@linouxis9

[linouxis9]

It seems you are using the same VM for PacketRusher and the UPF, make sure to use two distinct virtual machines as it can causes issues otherwise @Mouradnetworking

[Mouradnetworking]

How about considering Docker instead? It might help us avoid these issues @linouxis9.

Kind regards,

[linouxis9]

Yes, it's also supported running UPF and PacketRusher on the same host using Docker.
You may look at this amazing project from @Borjis131 for that: https://github.com/Borjis131/docker-open5gs

[Mouradnetworking]

Thank you! I'll give it a try and get back to you.