Accesing router from outside

adnansari · ‎03-30-2007

I am looking for some configuration help. I will be configuraing a stand alone 3725 router to access internet DS3. I have a public IP from the provider and looking for a basic config template. I would also like to access the router remotely from outside.

Amit Singh · ‎03-30-2007

Hello,

Please find the link below for configuring the NAT on the router:

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_tech_note09186a0080094e77.shtml

You can enable telnet on the router to access it from outside.Please configure the valid IP to access the router from outside

Conf t

username ABC password 123

enable secret 12345

access-list 1 permit host

Line vty 0 4

login local

access-class 1 in

transport input telnet

The link below will help you creating the telnet access-list to allow access from outside

http://www.cisco.com/warp/public/105/ACLsamples.html

HTH,

-amit singh

royalblues · ‎03-30-2007

Though the configuration mentioned by amit on the vty lines would be good from a security point of view, the access-list could be a problem if you get dynamic ip assignment from the ISP

I would suggest using SSH though

Narayan

adnansari · ‎03-30-2007

thanks for the reply.

Danilo Dy · ‎04-02-2007

If you are accessing your router from a single ISP outside, you can try to WHOIS your ISP netblock from one of the following (depends on your geographic location);

ARIN http://www.arin.net

APNIC http://www.apnic.net

LACNIC http://lacnic.net/en/

RIPE NCC http://www.ripe.net/

AFRINIC http://www.afrinic.net/

And put your ISP prefix in ACL 1. Some ISP have multiple prefixes for different use, ADSL, Office Connect, IDC, etc.. At least this way you have implemented some level of security which allows only "few" networks to be able to access your router. If in case your router is hacked, you know that the hacker is someone connected to your ISP and you can ask your ISP for the hacker details :)