help configuration for sub interface

[A7M876]

Hi,

today I received new IP address from the ISP and I really I can't configure my router for new IP

here is the new IP I had received.

Port: sub-interface (1115)

branch IP address : 87.101.135.100

Gateway: 87.101.135.6

DNS: 87.101.202.133

DNS: 87.101.203.9

please help me for configuration for sub-interface and up the network

[balaji.bandi]

what router you have, can you post the exiting configuration of the device?

we need to configure this pointing towards ISP side - that can be advise only once we see the exiting information.

[A7M876]

thanks for your replay

router model: 881

old router configuration:

ip name-server : 87.101.202.133

ip name-server: 87.101.203.9

interface fastethernet4

ip address: 87.101.135.100 255.255.255.252

ip nat inside

interface Vlan1

ip address: 192.168.1.1 255.255.255.0

ip nat outside

ip route 0.0.0.0 0.0.0.0 87.101.135.6

[balaji.bandi]

I do not belive you have provided correct information here : post full show run from device.

and i do not belive below config works.

interface fastethernet4   

ip address: 87.101.135.100 255.255.255.252

ip nat inside   - this always should be outside nat

interface Vlan1

ip address: 192.168.1.1 255.255.255.0

ip nat outside  - this should be inside nat since you are using private address space here

=================

interface fastethernet x/x

interface FastEthernet4

no ip address

duplex auto

speed auto

!

interface FastEthernet4.1

ip address  87.101.135.100 255.255.255.252

ip nat outside

!

interface FastEthernet4.1115

 ip address  87.101.135.100  mask.x.x.x252

add an additional static router to 87.101.135.6

you can use other interface ip nat outside depends on your requirement.

[A7M876]

this router configuration 

UCIC_Router#show run
UCIC_Router#show running-config
Building configuration...

Current configuration : 1944 bytes
!
! Last configuration change at 07:38:22 UTC Thu Nov 14 2019 by ucic
version 15.3
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname UCIC_Router
!
boot-start-marker
boot-end-marker
!
aqm-register-fnf
!
enable secret 5 $1$Ia.V$8JV7qaB/UWOT/9IXazVD4/
!
no aaa new-model
!
!
!
!
!
!

!
!
!
!
ip name-server  87.101.202.133
ip name-server 87.101.203.9
ip cef
no ipv6 cef
!
!
!
!
!
multilink bundle-name authenticated
!
!
!
!
!
!
!
license udi pid C881-K9 sn FCZ204613NU
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
interface FastEthernet0
 no ip address
!
interface FastEthernet1
 no ip address
!
interface FastEthernet2
 no ip address
!
interface FastEthernet3
 no ip address
!
interface FastEthernet4
 description " To ITC Modem "
  ip address 87.101.135.100 255.255.255.252
 ip nat outside
 ip virtual-reassembly in
 duplex auto
 speed auto
!
interface FastEthernet4.1
!
interface FastEthernet4.1115
!
interface Vlan1
 description " Conneted To Switch "
 ip address 192.168.1.1 255.255.255.0
 ip nat inside
 ip virtual-reassembly in
!
ip forward-protocol nd
no ip http server
no ip http secure-server
!
!
ip nat inside source list 101 interface FastEthernet4 overload
ip route 0.0.0.0 0.0.0.0  0.0.0.0 0.0.0.0 87.101.135.6
!
!
access-list 101 deny   ip any 192.168.1.0 0.0.0.255
access-list 101 permit ip 192.168.1.0 0.0.0.255 any
!
control-plane
!
!
!
mgcp behavior rsip-range tgcp-only
mgcp behavior comedia-role none
mgcp behavior comedia-check-media-src disable
mgcp behavior comedia-sdp-force disable
!
mgcp profile default
!
!
!
!
!

end

UCIC_Router#

[Jaderson Pessoa]

Well... we need more information about your environment to suggest a better solution.

Just suggestive exemple;  As our friends told to you.. we need more information to provide a better suggestion for your environment.

interface gi1/0.1115

ip address 87.101.135.100 255.255.255.128 ( check mask)

ip route  0.0.0.0 0.0.0.0 87.101.135.6

dns-servers 87.101.202.133 87.101.203.9

[A7M876]

still doesn't work 

#show running-config
Building configuration...

Current configuration : 2013 bytes

!
ip name-server 87.101.202.133
ip name-server 87.101.203.9
ip cef
no ipv6 cef
!
!
!
!
!
multilink bundle-name authenticated

interface FastEthernet0
 no ip address
!
interface FastEthernet1
 no ip address
!
interface FastEthernet2
 no ip address
!
interface FastEthernet3
 no ip address
!
interface FastEthernet4
 no ip address
 ip virtual-reassembly in
 duplex auto
 speed auto
!
interface FastEthernet4.1115
 description " TO ITC Modem "
 encapsulation dot1Q 60
 ip address 87.101.135.100 255.255.255.252
 ip nat outside
 ip virtual-reassembly in
!
interface Vlan1
 description " Conneted To Switch "
 ip address 192.168.1.1 255.255.255.0
 ip nat inside
 ip virtual-reassembly in
!
ip forward-protocol nd
no ip http server
no ip http secure-server
!
!
ip nat inside source list 101 interface FastEthernet4.1115 overload
ip route 0.0.0.0 0.0.0.0  0.0.0.0 0.0.0.0 87.101.135.6
!
!
access-list 101 deny   ip any 192.168.1.0 0.0.0.255
access-list 101 permit ip 192.168.1.0 0.0.0.255 any
!

[Jaderson Pessoa]

@A7M876  Hello

Please, provide changes below;

ip nat inside source list 101 interface FastEthernet4.1115 overload

no ip route 0.0.0.0 0.0.0.0  0.0.0.0 0.0.0.0 87.101.135.6    ( 87.101.135.6 is out of network range in  87.101.135.100 255.255.255.252 ), maybe is .99 or 101, check it)
ip route 0.0.0.0  0.0.0.0 87.101.135.99 or 101 ( check correctly ip address)

!
! access-list 101 deny ip any 192.168.1.0 0.0.0.255 << remove this line
no access-list 101 deny ip any 192.168.1.0 0.0.0.255
 access-list 101 permit ip 192.168.1.0 0.0.0.255 any !

[A7M876]

am erase the router but still same issue doesn't work

[Jaderson Pessoa · Accepted solution]

your configuration is wrong.

The gateway cant be 87.101.135.6/30 and network 87.101.135.100/30 because they are in different network

Network: 87.101.135.100/30           01010111.01100101.10000111.01100100 (Class A)
Broadcast: 87.101.135.103              01010111.01100101.10000111.01100111
HostMin: 87.101.135.101                 01010111.01100101.10000111.01100101
HostMax: 87.101.135.102                01010111.01100101.10000111.01100110

Network: 87.101.135.4/30               01010111.01100101.10000111.000001 00 (Class A)
Broadcast: 87.101.135.7                  01010111.01100101.10000111.000001 11
HostMin: 87.101.135.5                     01010111.01100101.10000111.000001 01
HostMax: 87.101.135.6                    01010111.01100101.10000111.000001 10

your addressing are wrong.. take correctly information with your ISP.