09-18-2009 10:47 PM - edited 03-06-2019 07:47 AM
Hello! I'm new to Cisco devices and now have troubles with routing from LAN to internet. My ISP offers PPTP connection via ethernet cable, and I'm trying to setup Cisco 871w (c870-advsecurityk9-mz.124-15.T7.bin). I managed to connect to ISP, so I'm now getting real ip and can ping/trace any remote host from router console. I can also ping router from desktop computers, but I can't ping default gateway or any other host in internet.
Network configuration is pretty simple. Desktops should go into 10.254.254.0 via ethernet or wifi (haven't tried it yet). Dialer17 connects to PPP server : ppp.inetvl.ru (172.16.4.1). Then it receives local ip address: 172.16.67.18, default gateway: 172.16.67.1.
ISP also gave me several static routes, I add them using `ip route`. So here goes `sh ru`:
--
Router#sh ru
Building configuration...
Current configuration : 2377 bytes
!
version 12.4
no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
service internal
!
hostname Router
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
!
!
dot11 syslog
no ip gratuitous-arps
ip cef
no ip dhcp use vrf connected
ip dhcp excluded-address 192.168.1.1
!
ip dhcp pool HOME
import all
network 192.168.1.0 255.255.255.0
default-router 192.168.1.1
dns-server 192.168.1.1
lease infinite
!
!
ip multicast-routing
!
vpdn enable
!
vpdn-group 22
request-dialin
protocol pptp
rotary-group 17
initiate-to ip 172.16.4.1
!
!
!
username admin privilege 15 secret 5 $1$nHUH$PqLKF4ejczfixqn0/3N5p.
!
!
archive
log config
hidekeys
!
!
!
!
!
interface FastEthernet0
!
interface FastEthernet1
!
interface FastEthernet2
!
interface FastEthernet3
!
interface FastEthernet4
mac-address 0023.5a6e.ebb7
ip address dhcp
ip nat outside
ip virtual-reassembly
duplex auto
speed auto
no cdp enable
!
interface Dot11Radio0
no ip address
shutdown
speed basic-1.0 basic-2.0 basic-5.5 6.0 9.0 basic-11.0 12.0 18.0 24.0 36.0 48.0
54.0
station-role root
!
interface Vlan1
ip address 192.168.1.1 255.255.255.0
ip nat inside
ip virtual-reassembly
ip tcp adjust-mss 1452
!
interface Dialer17
mtu 1450
bandwidth 100000
ip address negotiated
ip nat outside
ip virtual-reassembly
encapsulation ppp
dialer in-band
dialer idle-timeout 0
dialer string 123
dialer vpdn
dialer-group 22
no peer neighbor-route
no cdp enable
ppp pfc local request
ppp pfc remote apply
ppp encrypt mppe auto
ppp chap hostname ***
ppp chap password 0 ***
ppp ipcp dns request
!
ip forward-protocol nd
ip route 0.0.0.0 0.0.0.0 Dialer17
ip route 95.154.112.64 255.255.255.192 172.16.67.1
ip route 95.154.113.0 255.255.255.128 172.16.67.1
ip route 172.16.0.0 255.240.0.0 172.16.67.1
ip route 192.168.0.0 255.255.0.0 172.16.67.1
!
no ip http server
no ip http secure-server
ip dns server
ip nat inside source list 24 interface Dialer17 overload
!
access-list 23 permit 0.0.0.0 255.255.255.0
access-list 24 permit 0.0.0.0 255.255.255.0
dialer-list 22 protocol ip permit
no cdp run
!
!
!
control-plane
!
!
line con 0
login local
no modem enable
transport preferred telnet
line aux 0
line vty 0 4
login
!
scheduler max-task-time 5000
end
--
...So the problem is that I can only ping 172.16.67.18 from desktop, but I can't reach 172.16.67.1 or any other remote address. How do I share internet from router to other computers in LAN?
Thanks in advance.
Solved! Go to Solution.
10-01-2009 08:48 AM
Hello Nikolai,
if those ISP subnets have to be accessed without natting you need to exclude from translations those communications.
example
ip access-list extended NAT_TRAFFIC
deny ip 192.168.1.0 0.0.0.255 192.168.0.0. 0.0.255.255
deny ip 192.168.1.0 0.0.0.255 172.16.0.0 0.0.255.255
permit ip 192.168.1.0 0.0.0.255 any
in this way traffic for the internet is defined as all traffic not directed to ISP private subnets.
Hope to help
Giuseppe
09-19-2009 12:00 PM
Your acl for the NAT doesn't look right. Assuming it is meant to be "permit any" then change to -
access-list 24 permit 0.0.0.0 255.255.255.255
Jon
09-30-2009 06:12 PM
Thanks for reply, Jon, I almost got it. Now I have internet both on router and on desktop PCs. But still there's problem - can't access my ISP local resources.
Here's the scheme once again:
1. My Home LAN (fa0/3+wifi via BVI1): 192.168.1.0
2. FastEthernet4: 172.16.67.18 (gateway 172.16.67.1)
3. ISP LAN: 95.154.112.0, 95.154.113.0, 172.16.0.0, 192.168.0.0 (static routes)
4. Internet (PPTP via Dialer)
I made access-list with local IPs and created rule for overloaded NAT:
ip nat inside source list NAT_TRAFFIC interface Dialer17 overload
ip access-list extended NAT_TRAFFIC
permit ip 192.168.1.0 0.0.0.255 any
But in this case I can't access ISP LAN. If I change overloaded interface from Dialer to Fa4 I go into LAN, but Internet disappears) I made a picture just in case: http://yfrog.com/0uciscop
And config once again:
version 12.4
no service pad
service tcp-keepalives-in
service tcp-keepalives-out
service internal
!
dot11 ssid ***
vlan 1
authentication open
authentication key-management wpa
guest-mode
wpa-psk ascii 0 ***
!
ip source-route
no ip gratuitous-arps
!
!
no ip dhcp use vrf connected
ip dhcp excluded-address 192.168.1.1
!
ip dhcp pool HOME
import all
network 192.168.1.0 255.255.255.0
default-router 192.168.1.1
dns-server 192.168.1.1
lease 0 2
!
!
ip cef
ip multicast-routing
no ipv6 cef
!
multilink bundle-name authenticated
!
vpdn enable
!
vpdn-group 22
request-dialin
protocol pptp
rotary-group 17
initiate-to ip 172.16.4.1
!
!
!
bridge irb
!
!
interface FastEthernet0
!
interface FastEthernet1
!
interface FastEthernet2
!
interface FastEthernet3
!
interface FastEthernet4
mac-address 0023.****.****
ip address 172.16.67.18 255.255.255.0
ip verify unicast reverse-path
no ip redirects
no ip unreachables
no ip proxy-arp
ip flow ingress
ip nat inside
ip virtual-reassembly
duplex auto
speed auto
ntp broadcast client
no cdp enable
!
interface Virtual-Template1
mtu 1476
no ip address
!
interface Dot11Radio0
no ip address
!
encryption mode ciphers tkip
!
encryption vlan 1 mode ciphers tkip
!
broadcast-key change 3600
!
!
ssid ***
!
speed basic-1.0 basic-2.0 basic-5.5 6.0 9.0 basic-11.0 12.0 18.0 24.0 36.0 48.0
54.0
station-role root
l2-filter bridge-group-acl
no cdp enable
!
interface Dot11Radio0.1
encapsulation dot1Q 1 native
no cdp enable
bridge-group 1
bridge-group 1 subscriber-loop-control
bridge-group 1 spanning-disabled
bridge-group 1 port-protected
bridge-group 1 block-unknown-source
no bridge-group 1 source-learning
no bridge-group 1 unicast-flooding
!
interface Vlan1
no ip address
ip flow ingress
ip nat inside
ip virtual-reassembly
ip tcp adjust-mss 1452
load-interval 30
fair-queue
bridge-group 1
!
interface Dialer17
mtu 1476
bandwidth 100000
ip address negotiated
ip nat outside
ip virtual-reassembly
encapsulation ppp
dialer in-band
dialer idle-timeout 0
dialer string 123
dialer vpdn
dialer-group 22
no peer neighbor-route
no cdp enable
ppp pfc local request
ppp pfc remote apply
ppp encrypt mppe auto
ppp chap hostname ***
ppp chap password 0 ***
ppp ipcp dns request
!
interface BVI1
ip address 192.168.1.1 255.255.255.0
ip nat inside
ip virtual-reassembly
ip tcp adjust-mss 1452
!
ip default-gateway 172.16.67.1
ip forward-protocol nd
ip route 0.0.0.0 0.0.0.0 Dialer17
ip route 95.154.112.64 255.255.255.192 172.16.67.1
ip route 95.154.113.0 255.255.255.128 172.16.67.1
ip route 172.16.0.0 255.240.0.0 172.16.67.1
ip route 192.168.0.0 255.255.0.0 172.16.67.1
!
ip dns server
ip dns spoofing
ip nat inside source list NAT_TRAFFIC interface Dialer17 overload
!
ip access-list extended NAT_TRAFFIC
permit ip 192.168.1.0 0.0.0.255 any
!
dialer-list 22 protocol ip permit
no cdp run
!
!
control-plane
!
bridge 1 protocol ieee
bridge 1 route ip
!
10-01-2009 08:48 AM
Hello Nikolai,
if those ISP subnets have to be accessed without natting you need to exclude from translations those communications.
example
ip access-list extended NAT_TRAFFIC
deny ip 192.168.1.0 0.0.0.255 192.168.0.0. 0.0.255.255
deny ip 192.168.1.0 0.0.0.255 172.16.0.0 0.0.255.255
permit ip 192.168.1.0 0.0.0.255 any
in this way traffic for the internet is defined as all traffic not directed to ISP private subnets.
Hope to help
Giuseppe
10-07-2009 06:52 PM
Thank's, giuslar. It works this way:
ip nat inside source list NAT_INTERNET interface Dialer17 overload
ip nat inside source list NAT_ISP interface FastEthernet4 overload
!
ip access-list extended NAT_INTERNET
deny ip 192.168.1.0 0.0.0.255 172.16.0.0 0.0.255.255
deny ip 192.168.1.0 0.0.0.255 95.154.112.0 0.0.0.255
deny ip 192.168.1.0 0.0.0.255 95.154.113.0 0.0.0.255
deny ip 192.168.1.0 0.0.0.255 192.168.0.0 0.0.255.255
permit ip 192.168.1.0 0.0.0.255 any
ip access-list extended NAT_ISP
remark From home LAN to ISP LAN
permit ip 192.168.1.0 0.0.0.255 any
!
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