I have an NSA 2650, firmware v Running only a few of the security services including content filter, gateway AV, IP, RBL filter, GEO-IP, and botnet filter (no DPI-SSL!). I'm trying to allow some of our users to work remotely while dealing with this virus. It seems like they've been having trouble when connecting simultaneously, so I started wondering if our network bandwidth was limited somehow. Besides the firewall, the machines only run through one other unmanaged switch.

We are in a building that has a datacenter and we colo there so have direct connection to their redundant fiber connections. We have a 20Mbps connection included with our colo costs.

When I noticed this issue with the users and RDP, I asked the colo if there was something limiting our bandwidth for some reason. They said that there wasn't but that when they look at our traffic, it rarely ever exceeds 3Mbps. He said he saw 1 spike to 18-ish.

I ran a speed test just now and it averaged 17Mbps down and 17Mbps up, so not sure what is going on.

Is there something on the firewall that could be limiting speeds for some reason? We are using Chrome Remote Desktop, so it's mainly 443 traffic. I did have to open several outbound ports to get it working, but seems fine when it eventually connects. If there is something that could be limiting, what could it be and/or where can I look for culprits.

  • 1
    We need to see the configuration in order to tell for sure. You can edit your question to include the configuration using the preformatted text option. Note that enabling the security services greatly slows the firewall down. You could try turning some of them off temporarily to see if things improve.
    – Ron Trunk
    Apr 14 '20 at 19:36
  • Is there a preferred/typical way to dump the config so that I can post here? I usually just use the UI..Thx
    – stormdrain
    May 5 '20 at 20:11

It sounds like your ISP is saying they're not seeing the traffic exceed 3Mbs, but you're saying when you perform the test, it's around 17Mbs. Here's how we troubleshoot this:

1) Take a laptop, plug into into the gateway/modem (excluding the firewall altogether), run a speed test and verify you can access the internet.

2) Depending on the results, if the speeds are not what expected, the issue is with the Modem/ISP. if the speeds are expected, return the cable from the modem/gateway back to the designated WAN port of the sonicwall. Verify the cable is a cat 5e or 6. Go into your sonicwall WAN port and verify the negotiation speed is set to full/half/auto. Confirm those settings on both endpoint devices.

3) Run a packet capture, see if any packets are getting dropped/forwarded/consumed from the interfaces.

Not the answer you're looking for? Browse other questions tagged or ask your own question.