FortiClient VPN Problems With OSX 10.11 El Capitan

[danjahner]

I installed the GM candidate of Mac OS X 10.11 El Capitan and my FortiClient VPN has stopped working. It completes the login, but after connection, no data is transferred - the incoming and outgoing freeze. It is a split tunnel connection and neither network or internet traffic works. 

I tried disabling the firewall and System Integrity Protection, but neither had any effect. 

[lzs · Accepted solution]

I've been trying since the first public beta, and now on the final GM Candidate. The VPN problem is there. Basically, what is wrong is that OS X's resolver is sending traffic out through the primary (original) network interface, even though the route table correctly shows that the VPN tunnel (ppp0) should be used.

When you use a command like nslookup, the DNS traffic goes through the VPN tunnel (ppp0) properly.

DNS name resolution  fails because my VPN client is told to use my corporate DNS server, but my corporate DNS server refuses to serve name queries from outside the corporate network. When the FortiClient VPN is connected, OS X's name resolution traffic arrives at the DNS server with the client's public Internet IP address, and hence is refused by my DNS server.

Technically, this looks like an OS X bug. Or, perhaps there really is something wrong that FortiClient is dong. Either way, I hope FortiNet can rectify or take it up with Apple to fix El Capitan.

[Sridhar · Accepted solution]

Facing the same issue. Latest FortiClient(5.3*) did not fix it.

But, FortiClient 4.0.2082 did not have any such issues(though it occasionally stops tunneling on its own).

Waiting for a fix like everyone, but 4.0.2082 is letting me work for time being.

[hansbogert · Accepted solution]

I've gotten it to "work" by getting the DNS to use ppp0 and some route magic. Explanation is on: http://serverfault.com/questions/728702/how-to-get-forticlient-working-in-osx-el-capitan/728707#7287...

Let's hope either party fixes this, because running scripts after establishing VPN is quite cumbersome.

[Chris_Lin_FTNT · Accepted solution]

There is a new private build here:

https://dl.dropboxusercontent.com/u/58793690/mac/FortiClient_5.4.0.493_macosx.dmg

Would you guys give it a try?

[kevinboos · Accepted solution]

Chris.Lin wrote:

There is a new private build here:

https://dl.dropboxusercontent.com/u/58793690/mac/FortiClient_5.4.0.493_macosx.dmg

Would you guys give it a try?

It works for now! Thanks!

[tommy765 · Accepted solution]

Just ran El Capitan updates and it still does not work - bummer

[shenight · Accepted solution]

Chris.Lin wrote:

Here is another interim build b499.

https://dl.dropboxusercontent.com/u/58793690/mac/FortiClient_5.4.0.499_macosx.dmg

5.4.1 release may be available at the end of February.

P.S. b493 from previous post is different from the official 5.4.0 b493. Developer made the change after 5.4.0 was released.

Thanks ! I had same problems that other people since 3 months with forticlient and this new build fixes the issue!!! Great job!

[Chris_Lin_FTNT · Accepted solution]

Try this. A more recent build.

https://www.dropbox.com/s...bpx1VjzYAmiK00S9a?dl=0

[Chris_Lin_FTNT]

I have an FortiClient Mac interim build FortiClient_5.3.25.492_macosx.dmg here: https://www.dropbox.com/sh/cb0j4pxw1f8nq84/AABJBxUrmhiRfwHjAIBKe1DSa/mac?dl=0

Please try to see if it works for you.

[lzs]

Chris.Lin wrote:

I have an FortiClient Mac interim build FortiClient_5.3.25.492_macosx.dmg here: https://www.dropbox.com/sh/cb0j4pxw1f8nq84/AABJBxUrmhiRfwHjAIBKe1DSa/mac?dl=0

Please try to see if it works for you.

Hi Chris, thanks, it's really good to know that someone's working on this issue!

I've just tested the build but the problem is not resolved. It's a bit different now. The resolver's traffic is sent through the tunnel "ppp0", but with the wrong source IP. It's using the source IP of the Mac's physical interface (e.g. "en0") instead of the VPN tunnel IP.

Using the "nslookup" command does see the DNS queries going through the tunnel "ppp0" with the proper source IP address, so this command works.

Hope this helps you! :)

[Chris_Lin_FTNT]

I see.

How about clearing DNS cache, like this http://osxdaily.com/2014/11/20/flush-dns-cache-mac-os-x/

After this, does it still use wrong source IP?

[lzs]

Chris.Lin wrote:

I see.

How about clearing DNS cache, like this http://osxdaily.com/2014/11/20/flush-dns-cache-mac-os-x/

After this, does it still use wrong source IP?

Hi Chris,

It's still sending the DNS queries with the wrong source IP after the cache flush. I don't think the cache flush would help anyway, since the resolver is in fact trying to send out the queries.

Hope this helps.

[Chris_Lin_FTNT]

We have a problem to reproduce this issue :(  Maybe we installed 10.11 on another drive instead of upgrade?

I wonder how do you guys install 10.11?

[Jeff_FCT_FTNT]

Could you attached

1. the sslvpn log file

2. the ifconfig settings

3. FOS config file

thanks

[Jeff_FCT_FTNT]

And FCT config file too.

[lzs]

Chris.Lin wrote:

We have a problem to reproduce this issue :(  Maybe we installed 10.11 on another drive instead of upgrade?

I wonder how do you guys install 10.11?

I have El Capitan upgraded over Yosemite.

[jweber]

Would you advise people not to upgrade to El Capitan if we use a Forticlient SSL VPN?

[jweber]

Jeff: I'm having the same DNS problem, on a clean install. I sent you the logs and config files via PM -- let me know if you need anything else.