Network instability issues after enabling ISF - OS6560-P48X4

[Reginaldo]

Hello!

I'm experiencing an issue with the IP-Source-Filter (ISF) feature, which should bring the network back to normal, but the opposite is happening on one of our networks.
After enabling this feature, many users are complaining about losing connection to their computers. They usually remove the network cable and reconnect it to their computers, and the connection is restored, but sometimes this occurs several times a day.
I noticed that disabling ISF on that network returns everything to normal.
Also, looking at the ISF statistics, it's dropping a lot of packets, which doesn't occur on our other networks.

Note: This is the only network in our network that uses an Alcatel switch, model OS6860E-U28, as the main switch (distributing the fiber).
Software: Alcatel-Lucent Enterprise OS6560-P48X4 8.10.93.R03 GA, June 14, 2025


Does anyone know a possible cause for this?




Example statistics attached.


I appreciate any help!

[Cristek]

Hi,
I also had a few issues with ISF in the past and I now end up rarely using it. Usually I end up using policies and UNP to control what devices are allowed to do whatever. My issues were also related to users losing connectivity -same as you- so I'm very interested in learning if I simply configured it wrong or something

[Reginaldo]

Hi.

I have several Wi-Fi access points (APs) connected to these devices, but they are used in tunnel mode, not bridge mode.
In your opinion, even if they operate in tunnel mode, shouldn't I configure the ports for the APs with ISF?