topic Re: Application Slow with Router ACL in Switching

Application Slow with Router ACL

vamsi harish — Fri, 08 Mar 2019 21:03:46 GMT

Hi,

We have been facing a strange issue in our network. When we implement an ACL on a router or a L3 switch at branch end the Citrix App launch or any other web services are getting slow. But when we access the same application without ACL, it's very fast. I did check the latency from network side with and with out ACL, but didn't find any delay. Kindly suggest what can cause this kind of issue.

Thanks,

Re: Application Slow with Router ACL

Yachay — Mon, 11 Dec 2017 15:30:29 GMT

Please, could you add a simple diagram indicating which interface your ACL is applied on, hosts, direction and some lines of the ACL?

Re: Application Slow with Router ACL

Jon Marshall — Mon, 11 Dec 2017 18:00:58 GMT

You have probably blocked some ports that are needed such as DNS for name lookups etc.

Easiest thing to do is to temporarily add a deny line and log it so you can see what is being blocked.

Jon

Re: Application Slow with Router ACL

vamsi harish — Wed, 13 Dec 2017 08:39:12 GMT

We did the same and allowed the required dependencies which were getting blocked earlier. Now the application started working normal. Thanks for your response.