Could not open connection to the host, on port 23: Connect failed

[Punit Patel]

Can anyone please help with this telnet problem on CISCO 877 ADSL Router

I am trying to telnet into my ISP Router remotely using public IP which has been dynamically assigned to the router by the ISP.

I can Ping the Router and I can also go out to the internet on that router but, I can not telnet into that router from Inside the Network nor Outside the Network. There are no Firewalls involved.

I have tried to clear the config and reconfigure it again, it does not help, I have also applied same config on another CISCO 877 ADSL Router it still does not work.

ERROR i get on the Command Prompt: Could not open connection to the host, on port 23: Connect failed

I have shown some of the Show Run out put below if that helps,

ip nat inside source list 1 interface Dialer0 overload
!
access-list 1 permit x.x.x.x 0.0.0.7
dialer-list 1 protocol ip permit

line vty 0 4
password 7 ***********
login

Manny Thanks

Punit

[Giuseppe Larosa]

Hello Punit,

from inside internal vlan can you telnet to the internal private ip address ?

that is if 10.10.10.1/24 is the ip address of Vlan 1 SVI interface from PC 10.10.10.20 can you telnet  to 10.10.10.1?

Have you applied any ACL inbound on dialer0 interface?

Hope to help

Giuseppe

[Punit Patel]

Hello Giuseppe,

the only whay i can telnet into the router is if i plug my laptop to the router directly and assigning a public ip from the same subnet range.

there is only one IP address assigned to the router,  which is the Outside interface DIaler 0, Vlan 1 is set to ip unnumbered Dialer0 there is no Private IP involved in this config. Hope this answers your question.

Regards

Punit

[Giuseppe Larosa]

Hello Punit,

>> the only whay i can telnet into the router is if i plug my laptop to the  router directly and assigning a public ip from the same subnet range.

or the device is not able to route, or there is an ACL applied on the vty

post

sh run | beg line vty

sh ip route

taken from IOS shell

Hope to help

Giuseppe

[Punit Patel]

Find Below the Requested Sh run outputs

ADSL-ROUTER1#sh run | beg line vty
line vty 0 4
password 7 ***********
login
!
scheduler max-task-time 5000
end

I have removed the IP for security reasons

ADSL-ROUTER1#sh ip route

Gateway of last resort is 0.0.0.0 to network 0.0.0.0

     x.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
S       x.x.x.x/29 is directly connected, Vlan1
C       x.x.x.x/32 is directly connected, Dialer0
     x.0.0.0/32 is subnetted, 1 subnets
C       x.x.x.x is directly connected, Dialer0
S*   0.0.0.0/0 is directly connected, Dialer0

I also keep getting the message below on the console done know if this is part of the problem

Mar 13 07:17:32.213: %IP_VFR-4-FRAG_TABLE_OVERFLOW: Vlan1: the fragment table h
as reached its maximum threshold 16

Hope this output helps

Thanks

[blau grana]

Hello Punit,

Your configuration is little bit strange. You do not have any private addresses configured on router, ip unnumbered on Vlan1 so LAN devices will obtain public IPs but you still perform NAT on them.

I would assign some private range on Vlan1, configure DHCP and perform NAT on private addresses to translate them on Dialer public IP.

If this is no suitable for you, never mind.

Now try to add this to your config:

aaa new-model

aaa authentication login default local

username punit password YOUR_PWD

line vty 0 4

   no password 7 ***********

   no login

Best Regards

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