Sonicwall TZ170 drops connection on LAN side



  • 1. How essential is an additional firewall?
    I am using the firewall that comes with XP. However, recently I downloaded the free version of Zone Alarm. Is ZA really necessary and if so, how is it compared to other ones you might suggest in place of it. Thanks, Mark
  • 2. Does anyone know how to let mysql through ipfw/iptables/PF?
    I have an internal RFC 1918 computer lab that runs entirely on space and my firewall (within the internal lab) runs between and In ipfw I've allowed generously 05005 allow tcp from to any 3306 05006 allow tcp from to any 33400-33450 I'm not so concerned about 3306 per-se. I can modify my allowances of 3306 to suit my purposes. But what I've noticed is that the replies come back on ports higher than 3306 (namely 33400 and upwards.) These I've allowd for in my firewall) and all appears to be working splendidly. But I'd like to know how other people have done it. I've heard of people allowing only port 3306. But I can't see how this works if the replies are on higher ports. (I've tried allow tcp from any to any 3306 established. but that didn't work.) The only setup that worked is the one I've now got. Paulb
  • 3. updater comodo firewall and avira antivirus
    Hi, I've this problem: the comodo updater firewall is always on from yesterday. I use avira antivirus. Why? thanks

Sonicwall TZ170 drops connection on LAN side

Postby genoff2000 » Sat, 27 Jan 2007 21:01:59 GMT


The problem i am having is, i have 15 users connect to a SBS 2003

My config is

SBS 2003 with 1 Nic



Sonicwal IP LAN Side
WAN Port connects to ADSL

The is problem is that one 1 clients drops connection to the

All clients are dhcp and on the same ip range

When i ping i get no reply, but if i ping SBS server i get a reply.
I went to another client and tried to ping I get a reply.

If i unplug the client with the problem nic cable and put it back in
again i get a reply from 192168.0.1, but after a while it drops again.
No other user is having any problems.

All the client computers are WIN XP.

I have changed the nic in the client and the cat5 patch lead, but this
had made no difference.

This is an intermitting problem, it works then does not work and then
it works again.

Any help, advice would be great



Re: Sonicwall TZ170 drops connection on LAN side

Postby mak » Sat, 27 Jan 2007 22:42:49 GMT

if it's just one host on the LAN not receiving replies, I doubt it's a sonicwall problem, anyway: check the logs and arp 
entries on the sonicwall.
make sure your client *is* getting a valid dhcp adress, and that there aren't any duplicates,

also: do you have some firewall, anti-something on that particular client?


Re: Sonicwall TZ170 drops connection on LAN side

Postby genoff2000 » Sun, 28 Jan 2007 00:40:29 GMT

Thank M for you reply

I have checked the client and it does have a valid ip address, cause
when it cannot ping the sonicwall, it can ping the the
sbs 2003 server.  other clients can ping both, when this client cannot
only ping the sonicwall.

I have not tried to ping from the sonicwall to the the failed client to
see if this is working.

When i renew the dhcp sometimes that fixes it, but only for a short
while, if i unplug the nic cable and reconnect it again
that fixes it for a short while.

what should i be looking for in the arp table on the sonicwall



Re: Sonicwall TZ170 drops connection on LAN side

Postby jv » Sun, 28 Jan 2007 23:08:01 GMT

Niall: Here are some things I would check
a. does the client have any static network configuration settings?
b. try the problem client on different switch port on your firewall/

I had a similar issue with a friend of mine two days,who was trying to 
connect his laptop to his high speed cable connection...client would 
obtain a valid ip address fine from the approved network range but 
could not go anywhere on the internet...checked every possible setting/
configuraiton on his ie but did not find anything...finally it clicked 
on me to check his network card setting and there was the problem, 
apparently his son had used the laptop at college and had set a static 
dns entry.....after 2+ hours (of free work)....

so, give it try...
(somerset, pa)

Re: Sonicwall TZ170 drops connection on LAN side

Postby genoff2000 » Tue, 30 Jan 2007 02:41:08 GMT

Cheers J

I will give that a try, that was the next thing i was going to do, 
change port on switch.

I am also going to give the client a static ip address,


Re: Sonicwall TZ170 drops connection on LAN side

Postby mak » Wed, 31 Jan 2007 18:07:34 GMT

check if the sonicwall has an arp entry for the client mac, meaning they can "see"
each other on layer 2


Re: Sonicwall TZ170 drops connection on LAN side

Postby genoff2000 » Thu, 01 Feb 2007 05:58:09 GMT

Cheers Mak

I will check that out and let you know


Return to firewall


Who is online

Users browsing this forum: No registered users and 55 guest