Member Avatar for hbmarar

hi to all,

Please somebody help me...I have a small lan and need to rectify it. butapart from lan and novell netware ....there is nothing installed.

I need some new architecture because of the following.

Problem 1:
It is gateway.Has a networking hub connected and a dial up modem. It behaves for irritating me everyday...I don't know why ...the link and active lights wud not glow ...and I wud be touching here and there...and after spending many hours also it won't work....

But when later is viewed ....the link wud be up and cud be connected..

Problem 2. Gateway has just the norton 2005 installed but still there is virus in it and other system accesing the net through winproxy....

The applicatoins goes on crashing ...and some VXD NDIS referencing memeory addresses is common to see on monitor.

Please somebody couldhelp me with a better architecture...plz...

I have 2 broadband connections and one dial up account.I would like to have a linux box with one ethernet card to access the net thru LAN.Is it possible.

Thanking in advance for the patience and concern...and hopes i was able toconvey properly......

Marar

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Dani AI

Generated

Good call by to make malware cleanup the immediate priority — reinfection will continually mask hardware or architecture fixes. Once the infected machine is quarantined and cleaned, focus on two separate problems: physical/link reliability, then a simple, robust gateway design.

Immediate physical checks (quick checklist)

  • Replace the hub with an unmanaged switch. Hubs create collisions and are a frequent source of intermittent link problems.
  • Swap cables and ports: use a known-good Cat5/6 cable and try a different jack or a laptop on the same cable to isolate the bad segment.
  • Try a different NIC or port on the switch; bent pins, bad crimping or a failing hub port often causes the “touch it and it works” symptom.
  • Check device power and heat; failing hubs/switches and flaky NICs often behave intermittently before failing completely.

Gateway architecture — what works and when

  • If the Linux box will use a serial dial-up modem for Internet, a single Ethernet NIC is fine: the Linux machine provides LAN DHCP/DNS and routes/NAT the LAN to the ppp0 interface.
  • For broadband (DSL/cable) you normally want one interface to the WAN device and one for the LAN — so two NICs is the standard recommendation. For two broadband links you either need multiple NICs and multi-WAN routing on Linux, or a small dual-WAN appliance.

Minimal NAT example for a dial-up gateway (replace interface names as needed):

echo 1 > /proc/sys/net/ipv4/ip_forward

iptables -t nat -A POSTROUTING -o ppp0 -j MASQUERADE
iptables -A FORWARD -i eth0 -o ppp0 -j ACCEPT
iptables -A FORWARD -i ppp0 -o eth0 -m state --state RELATED,ESTABLISHED -j ACCEPT

Operational hardening
Keep infected hosts offline until cleaned, run offline rescue scans, keep OS/AV updated, run DHCP/DNS from the gateway and use simple firewall rules. For a small office, a replacement switch plus a dedicated gateway (Linux or a low-cost hardware router) will deliver far more stability than patching a single Windows gateway that’s become a general-use workstation.

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Member Avatar for zeroth

Hey Marar,

Sounds like you have multiple problems there. Probably the first thing to do is get rid of the virus. Go to the sub forum - Virus, Spyware and other nasties - it´s under Windows which is under Tech Talk. Post a HiJackThis file from the infected computer (if you need to download this, check out the threads on how to do this and there will be a link).

Start a separate thread to post your HJT file. Someone will help you in that forum and then we can try to get the rest of you system fixed...

And good luck...

commented: good help, thanks! +1
Member Avatar for hbmarar

hi,

Sorry..could not make out .....
I could make out the sub forum but do not find it easy with :- 'sending a Hijackthi log'.

Hope you would be patient enough with me if I am being ignorant ....

Well that is the state of my mind now after such a repetitive behaviour from the network.

Thanking you for the reply and concern shown and expecting your help and guidance sincerely,
I remain

Marar

Member Avatar for zeroth

Hi again, Marar,

OK, you first need to go to the forum called Virus, Spyware and other nasties.

That forum can be found under Tech Talk, just like this networking forum. Except you have to choose Microsoft Windows forum instead of networking. When you get to that forum, you will see the Virus forum underneath.

These threads will instruct you to run an antivirus program and several spyware and adware programs to get rid of anything that might have taken over your system.

Also, there are multiple threads there that discuss how to download HiJackThis, which is a troubleshooting program. Please read all the relevant threads until you can post a HiJackThis log in the Virus forum. Someone will help you from there and try to get rid of the virus, which is the first step to getting things cleaned up.

Member Avatar for zeroth

I´m glad you got it working, congratulations...

Member Avatar for hbmarar

hi guru,

Thanks for the reply and without asking for your willingness,I have added you to my buddy list.

Hope you wont mind and I once again thanks you for the concern and considerations you have shown to me and request the same in the future also.

Thanking you I remain
Harish Balakrishnan Marar

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