Yes, the security group allows icmp traffic as well as ssh traffic on top of the other default security group settings.

Selinux is running in permissive mode (so shouldn't be blocking anything) and firewalld is disabled.

We don't use apparmor.

I also am not an iptables expert, but I haven't seen anything in the rules that jump out to me as being problematic:

Here are the iptables rules:
# iptables -L
Chain INPUT (policy ACCEPT)
target     prot opt source               destination
ACCEPT     tcp  --  l21652.ldschurch.org  anywhere             multiport dports amqps,amqp /* 001 amqp incoming amqp_10.61.157.59 */
ACCEPT     tcp  --  anywhere             anywhere             multiport dports fs-agent /* 001 aodh-api incoming aodh_api */
ACCEPT     tcp  --  l21652.ldschurch.org  anywhere             multiport dports iscsi-target /* 001 cinder incoming cinder_10.61.157.59 */
ACCEPT     tcp  --  anywhere             anywhere             multiport dports 8776 /* 001 cinder-api incoming cinder_api */
ACCEPT     tcp  --  anywhere             anywhere             multiport dports armtechdaemon /* 001 glance incoming glance_api */
ACCEPT     tcp  --  anywhere             anywhere             multiport dports 8041 /* 001 gnocchi-api incoming gnocchi_api */
ACCEPT     tcp  --  anywhere             anywhere             multiport dports http /* 001 horizon 80 incoming */
ACCEPT     tcp  --  anywhere             anywhere             multiport dports commplex-main /* 001 keystone incoming keystone */
ACCEPT     tcp  --  l21652.ldschurch.org  anywhere             multiport dports mysql /* 001 mariadb incoming mariadb_10.61.157.59 */
ACCEPT     tcp  --  anywhere             anywhere             multiport dports 9696 /* 001 neutron server incoming neutron_server_10.61.157.59 */
ACCEPT     udp  --  l21652.ldschurch.org  anywhere             udp dpt:geneve /* 001 neutron tunnel port incoming neutron_tunnel_10.61.157.59_10.61.157.59 */
ACCEPT     tcp  --  anywhere             anywhere             multiport dports 8773,8774,8775,uec /* 001 nova api incoming nova_api */
ACCEPT     tcp  --  l21652.ldschurch.org  anywhere             multiport dports rfb:cvsup /* 001 nova compute incoming nova_compute */
ACCEPT     tcp  --  l21652.ldschurch.org  anywhere             multiport dports 16509,49152:49215 /* 001 nova qemu migration incoming nova_qemu_migration_10.61.157.59_10.61.157.59 */
ACCEPT     tcp  --  anywhere             anywhere             multiport dports 6080 /* 001 novncproxy incoming */
ACCEPT     tcp  --  anywhere             anywhere             multiport dports 6641 /* 001 ovn northd incoming ovn_northd_10.61.157.59 */
ACCEPT     tcp  --  anywhere             anywhere             multiport dports 6642 /* 001 ovn southd incoming ovn_southd_10.61.157.59 */
ACCEPT     tcp  --  l21652.ldschurch.org  anywhere             tcp dpt:redis /* 001 redis service incoming redis service from 10.61.157.59 */
ACCEPT     tcp  --  anywhere             anywhere             multiport dports webcache /* 001 swift proxy incoming swift_proxy */
ACCEPT     tcp  --  l21652.ldschurch.org  anywhere             multiport dports x11,6001,6002,rsync /* 001 swift storage and rsync incoming swift_storage_and_rsync_10.61.157.59 */
ACCEPT     all  --  anywhere             anywhere             state RELATED,ESTABLISHED
ACCEPT     icmp --  anywhere             anywhere
ACCEPT     all  --  anywhere             anywhere
ACCEPT     tcp  --  anywhere             anywhere             state NEW tcp dpt:ssh
REJECT     all  --  anywhere             anywhere             reject-with icmp-host-prohibited

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination
ACCEPT     all  --  anywhere             anywhere             /* 000 forward in */
ACCEPT     all  --  anywhere             anywhere             /* 000 forward out */
REJECT     all  --  anywhere             anywhere             reject-with icmp-host-prohibited

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

Thanks!
Collin

From: Eugen Block <eblock@nde.ag>
Sent: Monday, February 3, 2025 8:20 AM
To: openstack-discuss@lists.openstack.org <openstack-discuss@lists.openstack.org>
Subject: [Ext:] Re: openstack instances unable to reach the internet
 
[External Email]

We use flat,vlan and vxlan.
Did you check if the instance's security-group allows icmp traffic? Is
there anything else potentially blocking traffic like firewalld,
apparmor, selinux and so on?
I guess looking at iptables could help here as well, but I'm not sure
if I can really help with that.

Zitat von collinl@churchofjesuschrist.org:

> Eugen, Thank you very much for your response.
>
> What network type do you typically use?  flat? vxlan?
>
> I don't believe that there is routing between the controller/compute
> node and the gateway. . .and from my testing that is where the pings
> are getting lost.
>
> Here is an example from the cirros instance pinging the
> controller/compute node (successfully), and the external gateway(not
> successfully):
> $ ping 10.61.157.59
> PING 10.61.157.59 (10.61.157.59): 56 data bytes
> 64 bytes from 10.61.157.59: seq=0 ttl=63 time=1.378 ms
> 64 bytes from 10.61.157.59: seq=1 ttl=63 time=1.317 ms
> 64 bytes from 10.61.157.59: seq=2 ttl=63 time=0.901 ms
> ^C
> --- 10.61.157.59 ping statistics ---
> 3 packets transmitted, 3 packets received, 0% packet loss
> round-trip min/avg/max = 0.901/1.198/1.378 ms
> $ ping 10.61.157.1
> PING 10.61.157.1 (10.61.157.1): 56 data bytes
> ^C
> --- 10.61.157.1 ping statistics ---
> 9 packets transmitted, 0 packets received, 100% packet loss
>
> How would I go about determining what is causing the packets to get
> lost at that point?
>
>> From the host 10.61.157.59 itself, it CAN ping the 10.61.157.1
>> gateway just fine. . .and all sites externally (i.e. 8.8.8.8)
>
> here is the traceroute output from the controller/compute node,
> showing a successful output, and with only one hop. . .so I don't
> think there is anything between the host and the gateway network wise:
> # traceroute 10.61.157.1
> traceroute to 10.61.157.1 (10.61.157.1), 30 hops max, 60 byte packets
>  1  _gateway (10.61.157.1)  0.374 ms  0.322 ms  0.297 ms