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NAT whit TTL=1

My ISP give me a real IP, but restrict whit TTL=1 and i want NAT to my network My router is 1811.

and Ihave vlan1 on

FOR NAT I use this:

Router(config)#interface FastEthernet0

Router(config-if)#ip nat outside

Router(config)#interface Vlan1

Router(config-if)#ip nat inside

Router(config)#ip nat inside source list 15 interface FastEthernet0 overload

Router(config)#access-list 15 permit

But I don't have internet

I thing this is from my ISP whit TTL=1



Re: NAT whit TTL=1

I do not understand why and how they restrict whit TTL=1 ? If it is, the next hop router (should be ISP router) will reduce TTL=0 and the packet will be dropped!

You can traceroute from inside PC to verify. if the packet can reach ISP router and dropped, so it is ISP' problems, call them to complain!

good luck


Re: NAT whit TTL=1

this not help me. My ping to ISP from WinXP2 is:

C:\Documents and Settings\Administrator>ping x.y.z.1

Pinging x.y.z.1 with 32 bytes of data:

Reply from x.y.z.1: bytes=32 time=1ms TTL=1

Reply from x.y.z.1: bytes=32 time<1ms TTL=1

Reply from x.y.z.1: bytes=32 time=2ms TTL=1

Reply from x.y.z.1: bytes=32 time=1ms TTL=1

where x.y.z.1 is my ISP Default Gateway, but

when i ping is my ip addres- then TTL=128

I try install Cisco router 1811 whit NAT outside addres x.z.z.100/24 and inside addres, but no heve internet :((


Re: NAT whit TTL=1

Please try

tracert -d

on your winxp PC and paste the result


Re: NAT whit TTL=1

C:\Documents and Settings\Administrator>tracert -d

Tracing route to over a maximum of 30 hops

1 2 ms 1 ms <1 ms x.y.z.1

2 3 ms 1 ms 2 ms

3 * * * Request timed out.

4 37 ms 38 ms 37 ms

5 42 ms 42 ms 42 ms

6 124 ms 131 ms 124 ms

7 136 ms 131 ms 137 ms

8 125 ms 126 ms 124 ms

Trace complete.

This is result from my WinXp whit real IP give from ISP


Re: NAT whit TTL=1

That good! I think you already have your internet up and running !!!

probably you need to confirm your DNS is working . I guess that the reason you think your internet not work! also check your ACL.


#show log

Good luck

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