12-28-2021 02:29 PM
Configuration snippets:
vlan 80 name untrusted by port
untagged ethe 3/1/3
ip access-group untrusted ininterface ve 80
ip address 192.168.80.2/24
ip access-list extended untrusted
enable accountingsequence 10 permit tcp any 192.168.0.0/16 established
sequence 20 permit icmp any any
sequence 30 permit udp any host 192.168.255.2 eq dns
sequence 40 permit tcp any host 192.168.255.2 eq dns
sequence 50 permit udp any host 192.168.255.1 eq ntp
sequence 60 permit tcp any host 192.168.64.113 eq ssl
sequence 70 deny tcp any 192.168.0.0/16
sequence 80 deny udp any 192.168.0.0/16sequence 90 permit tcp any any
sequence 100 permit udp any any
System attached to 3/1/3 has IP address 192.168.68.200/24, with its gateway set to 192.168.80.2.
With the above access-list that system is able to open TCP connections to 192.168.1.1, even though the initial SYN packet should not count as 'established'. If I remove the sequence 10 filter from the access-list, the system is no longer able to open such connections.
12-28-2021 03:07 PM
Hi Kevin,
Hope you are doing Great.
sequence 10 should not allow sync and sequence 70 will block everything.
Can you please go with 809k code?
This will need to be lab tested and fixed in the code.
Here is the link to the target poath
Hope this helps.
Sorry for the inconvenience.
Thanks
Best Regards
Hashim
Thanks
Best Regards
Hashim
12-28-2021 03:41 PM
Thanks for the quick response! Unfortunately I'm not able to use the 08 firmware, and I experienced very unusual problems with IPv6 routing with that firmware and the 09 firmware does not have those problems... and I don't have a lab environment in which to test alternative firmware versions 🙂
I believe I'll be able to work around this problem though by using a 'mirror' filter in the access-list in the VLAN where the connections originate (which land in VLAN 80). I'll experiment with that.
12-29-2021 05:19 AM
Ahh, ignore that, I misunderstood what 'mirror' does in access-list filters. I thought it was related to reflexive filters, but it's not.
12-29-2021 08:03 AM
Hi Kevin - We did some tests in the lab and found a workaround for this issue. It seems like a bug in this area, and we need to investigate further. For sequence 10, please use /24 instead of /16. Keep sequence 70/80 with /16 for now.
Also, we need to clarify this statement from your initial post: "System attached to 3/1/3 has IP address 192.168.68.200/24, with its gateway set to 192.168.80.2." We would assume you meant 192.168.80.200/24 for the host?
Please see the workaround below.
config t
ip access-list extended untrusted
no sequence 10
sequence 10 permit tcp any 192.168.80.0/24 established
Please try this and let us know if it helped.
Thank you,
Vu Pham
Principal Technical Support Engineer
Shift hours: 08:00-17:00 US Central (Mon-Fri)
CommScope