Can't Ping Outside via Serial Interfaces, works with FastEthernet

Hello,

I have the following setup:

Router 2

Serial

Router 1

Internet

10.1.1.2/24 10.1.1.1/24 192.168.1.254/24 192.168.2.1/24

I can ping from Router 2 to 192.168.1.254 with success
I can ping from Router 1 to 10.1.1.2 with success

I can't ping from Router 2 to 192.168.1.1 via a SERIAL connection between Router 2 and Router 1 it works however with Ethernet

Please, can someone explain why?

Thanks in advance.

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awinter

Router 2

Serial

Router 1

Internet

10.1.1.2/24

10.1.1.1/24

192.168.1.254/24

192.168.2.1/24

DCD

Supply the configuration for the R1 and R2. From the information you provide you misconfigured the one of the routers.

Ltat42a

If using serial cables, did you set a clock rate on the DCE end of the cable?

dontstop

Do you have a routing protocol running? Sounds like maybe the Ethernet is working due to proxy arp. Routing only know about directly connected networks without a routing protocol the pings will fail (note: proxy arp) to networks the router isn't directly connected to.

awinter

Here are the two configs

R1

version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
service password-encryption
!
hostname R1
!
boot-start-marker
boot-end-marker
!
enable secret 5 $1$iW5B$.Gs35kpDvY1EPullF.b1S/
!
no aaa new-model
clock timezone NL -3 30
clock summer-time NDT recurring
no network-clock-participate slot 1
no network-clock-participate wic 0
ip cef
!
!
no ip dhcp use vrf connected
ip dhcp excluded-address 192.168.1.1 192.168.1.49
ip dhcp excluded-address 192.168.10.1 192.168.10.49
ip dhcp excluded-address 192.168.20.1 192.168.20.49
!
ip dhcp pool HOME
network 192.168.1.0 255.255.255.0
default-router 192.168.1.1
dns-server 8.8.8.8 4.2.2.2
!
ip dhcp pool Pool10
network 192.168.10.0 255.255.255.0
default-router 192.168.10.1
dns-server 8.8.8.8 4.2.2.2
!
ip dhcp pool Pool20
network 192.168.20.0 255.255.255.0
default-router 192.168.20.1
dns-server 8.8.8.8 4.2.2.2
!
!
no ip domain lookup
ip domain name homebase.net
ip auth-proxy max-nodata-conns 3
ip admission max-nodata-conns 3
!
username andrew privilege 15 password 7 01100F175804
!
!
interface FastEthernet0/0
ip address 192.168.2.254 255.255.255.0
ip nat outside
ip virtual-reassembly
duplex auto
speed auto
!
interface Serial0/0
ip address 10.1.1.1 255.255.255.0
!
interface FastEthernet0/1
ip address 192.168.1.1 255.255.255.0
ip nat inside
ip virtual-reassembly
duplex auto
speed auto
!
interface FastEthernet0/1.10
encapsulation dot1Q 10
ip address 192.168.10.1 255.255.255.0
ip nat inside
ip virtual-reassembly
!
interface FastEthernet0/1.20
encapsulation dot1Q 20
ip address 192.168.20.1 255.255.255.0
ip nat inside
ip virtual-reassembly
!
router rip
version 2
network 10.0.0.0
network 192.168.1.0
network 192.168.2.0
network 192.168.10.0
network 192.168.20.0
!
ip default-gateway 192.168.2.1
ip forward-protocol nd
ip route 0.0.0.0 0.0.0.0 192.168.2.1
!
!
no ip http server
no ip http secure-server
ip nat inside source list NAT_ADDRESSES interface FastEthernet0/0 overload
!
ip access-list standard NAT_ADDRESSES
permit 192.168.1.0 0.0.0.255
permit 192.168.10.0 0.0.0.255
permit 192.168.20.0 0.0.0.255
!
control-plane
!
line con 0
exec-timeout 0 0
password 7 110A1016141D
logging synchronous
login local
line aux 0
login local
line vty 0 4
exec-timeout 0 0
password 7 0822455D0A16
logging synchronous
login local
transport input telnet ssh
!
ntp clock-period 17180043
ntp server 50.22.155.163
!
end

R1#

AND HERE IS R2

version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
service password-encryption
!
hostname R2
!
boot-start-marker
boot-end-marker
!
enable secret 5 $1$wWEN$3lvonIc5JcQh2Z.a/sylE1
!
no aaa new-model
clock timezone NL -3 30
clock summer-time NDT recurring
ip cef
!
!
!
!
no ip domain lookup
ip domain name homebase.net
!
!
username andrew privilege 15 secret 5 $1$oIVK$FsdL65yQ9VNtJpDgRjfLe1
!
!
ip ssh version 2
!
!
interface FastEthernet0/0
ip address dhcp
duplex auto
speed auto
!
interface FastEthernet0/1
ip address dhcp
duplex auto
speed auto
!
interface Serial0/0/0
ip address 10.1.1.2 255.255.255.0
no fair-queue
!
router rip
version 2
network 10.0.0.0
!
ip forward-protocol nd
ip route 0.0.0.0 0.0.0.0 10.1.1.1
ip route 0.0.0.0 0.0.0.0 Serial0/0/0
!
ip http server
no ip http secure-server
!
!
control-plane
!
!
line con 0
exec-timeout 30 0
password 7 01100F175804
logging synchronous
login local
line aux 0
exec-timeout 30 0
password 7 094F471A1A0A
logging synchronous
login local
line vty 0 4
exec-timeout 30 0
password 7 00071A150754
logging synchronous
login local
!
scheduler allocate 20000 1000
ntp clock-period 17179076
ntp server 192.168.2.254
end

This is the output of R1# show ip route

R1#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route

Gateway of last resort is 192.168.2.1 to network 0.0.0.0

C 192.168.10.0/24 is directly connected, FastEthernet0/1.10
C 192.168.20.0/24 is directly connected, FastEthernet0/1.20
10.0.0.0/24 is subnetted, 1 subnets
C 10.1.1.0 is directly connected, Serial0/0
C 192.168.1.0/24 is directly connected, FastEthernet0/1
C 192.168.2.0/24 is directly connected, FastEthernet0/0
S* 0.0.0.0/0 [1/0] via 192.168.2.1
R1#

This Show IP Route R2

R2#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route

Gateway of last resort is 10.1.1.1 to network 0.0.0.0

R 192.168.10.0/24 [120/1] via 10.1.1.1, 00:00:21, Serial0/0/0
R 192.168.20.0/24 [120/1] via 10.1.1.1, 00:00:21, Serial0/0/0
10.0.0.0/24 is subnetted, 1 subnets
C 10.1.1.0 is directly connected, Serial0/0/0
C 192.168.1.0/24 is directly connected, FastEthernet0/1
R 192.168.2.0/24 [120/1] via 10.1.1.1, 00:00:21, Serial0/0/0
S* 0.0.0.0/0 [1/0] via 10.1.1.1
is directly connected, Serial0/0/0
R2#

Remember the problem is I cannot PING 192.168.2.1 from R2 or connect to the 192.168.2.X network. I can ping 192.168.2.254 only.

Thanks in advance.

DCD

Your configuration is confusing you have
Router 2

Serial

Router 1

Internet

10.1.1.2/24

10.1.1.1/24

192.168.1.254/24

192.168.2.1/24

But yourrouter config is this

R1
interface FastEthernet0/0
ip address 192.168.2.254 255.255.255.0
ip nat outside
ip virtual-reassembly
duplex auto
speed auto

interfaceFastEthernet0/1
ip address 192.168.1.1 255.255.255.0
ip nat inside
ip virtual-reassembly
duplex auto
speed auto

You have two different subnets between R1 and the Internet.I don’t know why on R1 you have ip default-gateway 192.168.2.1 and ip route0.0.0.0 0.0.0.0 192.168.2.1. You have sub-interface on f0/1 and using a IPaddress on F0/1.
I not sure what youare trying do but I would redo R1. Set a static IP address on the Ethernet interfaceand I would have the NAT changing the 10.1.1.0/24 to 192.168.2.X/24 network.Also if you could put description for the interface.

tunerX

Router 1 uses an inside source list that only includes the 192 networks. Router 2 will be using a 10 network as its source address.

Also you would need ip nat inside on the serial interface of router 1.

awinter

Hi, Thanks all for your input. TunerX put me on the right path. Problem was ip nat inside was not declared for the serial interface and the ACL NAT_ADDRESSES did not have the 10.1.1.0 network allowed. Problem solved!

Thanks again!