topic Re: How to disable SIP ALG inspection in a specific rule in Checkpoint? Also Could this be done glob in Firewall and Security Management

How to disable SIP ALG inspection in a specific rule in Checkpoint? Also Could this be done globally, like Cisco ASA?

Deepak_Chauhan — Thu, 25 Jan 2018 08:27:23 GMT

Re: How to disable SIP ALG inspection in a specific rule in Checkpoint? Also Could this be done globally, like Cisco ASA?

Tomer_Sole — Thu, 25 Jan 2018 09:02:30 GMT

You can do this by creating exception for this inspection setting.

Re: How to disable SIP ALG inspection in a specific rule in Checkpoint? Also Could this be done globally, like Cisco ASA?

Hugo_vd_Kooij — Mon, 29 Jan 2018 09:55:26 GMT

Actually I am not sure Tomer answer will work. After having been on first name bases with R&D VOIP for a year with loads of VOIP tickets in R65 I learned a lot of the background of the code. And I guess most of it is still valid.

At least in R77.30 I always use the following strategy:

Define your own UDP or TCP object without a protocol handler. For example: Name it SIP-BARE and use UDP/5600
Make sure you enable "Match for Any" on your own service and disable it on the existing service.
Make a rule for you own service AND!!!! make sure it is ABOVE any rule that uses the build in SIP services (which contains handlers).

If you forget to put your rule in the right order the whole trick will not work.

As soon as you have a rule that will contain a handler for a specific TCP or UDP port that decision will stick.

So if you have a generic SIP on rule 30 and your own definition on rule 40 you will still see the SIP handler act on those connections.

If you put your own definition in rule 28 and have generic SIP in rule 30 then rule 28 will not act on SIP traffic but rule 30 will still act on SIP traffic and do all sorts of magic.

I must admit this is a tricky concept to understand at first but once you understand these basics you can explain a lot of unexpected behaviour in Check Point firewalls.

So far I have not been able to verify this is still how it works with R80.10 and I have yet to add a PABX to my lab. (Actually I have a 3CX PABX but it has some other issues I need to sort out first.)

Re: How to disable SIP ALG inspection in a specific rule in Checkpoint? Also Could this be done globally, like Cisco ASA?

Noam_Warhaftig — Tue, 30 Jan 2018 08:25:38 GMT

Your solution should work on R80.10 as well.

Please make sure that voip_multik_enable_forwarding param is off when no SIP inspection needed to avoid heavy performance issues.

Re: How to disable SIP ALG inspection in a specific rule in Checkpoint? Also Could this be done glob

jerryroy1 — Tue, 09 Apr 2019 20:09:06 GMT

Like This you mean?

Re: How to disable SIP ALG inspection in a specific rule in Checkpoint? Also Could this be done glob

jerryroy1 — Fri, 26 Apr 2019 16:15:49 GMT

Are you replying to Hugo's method or Tomer?

Re: How to disable SIP ALG inspection in a specific rule in Checkpoint? Also Could this be done glob

jerryroy1 — Fri, 26 Apr 2019 16:23:00 GMT

What are the exceptions settings?

Re: How to disable SIP ALG inspection in a specific rule in Checkpoint? Also Could this be done glob

raider45 — Sat, 14 Sep 2019 19:56:41 GMT

Two questions :

Is a good idea to disable ALG inspection?
Where is this setting on the 700 smb series devices?

Thank you

Re: How to disable SIP ALG inspection in a specific rule in Checkpoint? Also Could this be done glob

Baasanjargal_Ts — Sun, 29 Mar 2020 08:23:10 GMT

SIP works on UDP 5060 port.

Re: How to disable SIP ALG inspection in a specific rule in Checkpoint? Also Could this be done glob

Julian_Sanchez — Fri, 13 Nov 2020 05:31:28 GMT

Hello

I have a question about security risk from disabling SIP ALG inspection. to disable SIP ALG by creating an exception for Block SIP Early Media on this inspection setting

Re: How to disable SIP ALG inspection in a specific rule in Checkpoint? Also Could this be done glob

enkhnasan — Tue, 08 Jun 2021 06:36:41 GMT

how about 1800 series ?

Re: How to disable SIP ALG inspection in a specific rule in Checkpoint? Also Could this be done glob

Cosmos_91 — Wed, 14 Sep 2022 08:11:15 GMT

You should Disable Inspection for this device in network object menu !