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Cisco 1710 Change Static IP Address

During SDSL upgrade from 256K to 1M, the ISP changed static IP address from 216.153.xxx.xx/24 to 64.65.xxx.xxx/30

I attached laptop to the ISP equipment with the new static IP allocation, and I verified external connectivity (I was able to route out past the ISP).

I changed the IP address on the Ethernet0 interface using:

Config-if# ip address 64.65.xxx.xxx
#wr mem

From there I can ping gateway, but not out past the gateway.  I can only imagine that I am missing something in the configuration (which I have included below).  Is there something other than the ethernet0 interface that needs to be modified?

I would appreciate any assistance.

Current configuration : 2622 bytes
version 12.2
service timestamps debug uptime
service timestamps log uptime
service password-encryption
hostname Band
enable password 7
memory-size iomem 15
ip subnet-zero
no ip domain-lookup
ip inspect name myfw http java-list 98
ip inspect name myfw tcp
ip inspect name myfw udp
ip inspect name myfw tftp
ip inspect name myfw ftp
ip inspect name myfw realaudio
ip inspect name myfw fragment maximum 256 timeout 1
ip inspect name myfw cuseeme
ip inspect name myfw vdolive
ip inspect name myfw sqlnet
ip inspect name myfw streamworks
ip inspect name myfw smtp
ip inspect name myfw h323
ip inspect name myfw rcmd
ip inspect name fwin tcp
ip inspect name fwin udp
ip audit notify log
ip audit po max-events 100
ip ssh time-out 120
ip ssh authentication-retries 3
crypto isakmp policy 11
 hash md5
 authentication pre-share
crypto isakmp key minda address 64.65.xxx.xx
crypto ipsec transform-set strong esp-des esp-md5-hmac
crypto mib ipsec flowmib history tunnel size 200
crypto mib ipsec flowmib history failure size 200
crypto map mymap 11 ipsec-isakmp
 set peer 64.65.xxx.xx
 set transform-set strong
 match address 120
interface Ethernet0
 description connected to Internet
 ip address 216.153.xxx.xx
 ip access-group 110 in
 ip nat outside
 ip inspect myfw in
 ip inspect myfw out
 crypto map mymap
interface FastEthernet0
 description connected to Beth_4th
 ip address 10.6.xxx.xx
 ip nat inside
 speed auto
router rip
 version 2
 passive-interface Ethernet0
 no auto-summary
ip nat inside source route-map nonat interface Ethernet0 overload
ip classless
ip route Ethernet0
no ip http server
ip pim bidir-enable
access-list 98 permit
access-list 101 deny   ip 10.6.xxx.xx
access-list 101 permit ip 10.6.xxx.xx any
access-list 110 permit esp any any
access-list 110 permit udp any any eq isakmp
access-list 110 permit tcp any host 216.153.xxx.xx eq telnet
access-list 110 permit icmp any any echo-reply
access-list 110 permit icmp any any echo
access-list 110 permit icmp any any unreachable
access-list 110 permit icmp any any time-exceeded
access-list 110 permit ip any
access-list 110 permit ahp any any
access-list 120 permit ip 10.6.xxx.xx
route-map nonat permit 5
 match ip address 101
line con 0
 exec-timeout 0 0
 password 7
line aux 0
line vty 0 4
 password 7
no scheduler allocate
RoutersNetwork Operations

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Last Comment

8/22/2022 - Mon

Is this config from before you changed it? It shows.

interface Ethernet0
 description connected to Internet
 ip address 216.153.xxx.xx

Also you still have this in your ACL that you might want to change if telnet is needed.

access-list 110 permit tcp any host 216.153.xxx.xx eq telnet



At this point, configuration is being done via console, so telnet is not of any concern.  That can be addressed once I've got the Internet connectivity established.

The posted configuration is the current / working configuration.  So, I seek assistance with making the requisite changes with the new IP addresses, specifically 64.65.xxx.xxx/30

Ok, These are the commands that you need to enter.   With the correct IP's of course.

Conf t
int e0
no  ip address 216.153.xxx.xx
ip address 64.65.xxx.xxx

wr mem

That should do it.  

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According to these links, using the address instead of the interface seems to be preferred.


Since your are using RIP, it can change how that route shows up (connected vs static), and whether it gets advertised.  It may need to be redistributed.