Cisco 877 Issue - Could be Nat?

Phil Bartlett · ‎03-03-2014

Hi

I'm setting up a VDSL/ADSL2+ DSLAM in test lab. I'm using a Cisco877 to test out the intial config. The 877 can connect and sync however it cant ping any devices on the DLSAM network .The CISCO877 is configured to use NAT and i think NAT is the issue here. Its has been sometime since i configured NAT and i'm sure it is something relativility simple.

DSLAM network is 10.3.1.x

CISCO877 Internal network 192.168.99.x

Config of the CISCO877

version 12.4
no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname Router
!
boot-start-marker
boot-end-marker
!
logging message-counter syslog
!
no aaa new-model
!
!
dot11 syslog
ip source-route
!
!
ip cef
ip domain name comtek.co.uk
!
!
!
!
!
!
!
archive
log config
hidekeys
!
!
!
bridge irb
!
!
interface ATM0
no ip address
no ip redirects
no ip unreachables
no ip proxy-arp
no atm ilmi-keepalive
dsl enable-training-log
!
interface ATM0.1 point-to-point
description DSL Link
ip virtual-reassembly
atm route-bridged ip
pvc 8/35
encapsulation aal5snap
!
bridge-group 1
!
interface FastEthernet0
!
interface FastEthernet1
!
interface FastEthernet2
!
interface FastEthernet3
!
interface Vlan1
ip address 192.168.99.1 255.255.255.0
ip nat inside
ip virtual-reassembly
!
interface BVI1
ip address 10.3.1.12 255.255.255.0
ip nat outside
ip virtual-reassembly
!
no ip forward-protocol nd
ip route 0.0.0.0 0.0.0.0 10.3.1.1
no ip http server
no ip http secure-server
!
ip nat inside source list 101 interface BVI1 overload
!
access-list 101 permit ip 192.168.99.0 0.0.0.255 any
!
!
!
!
control-plane
!
bridge 1 protocol ieee
bridge 1 route ip
!
line con 0
no modem enable
line aux 0
line vty 0 4
login
!
scheduler max-task-time 5000
end

Router#sh arp
Protocol Address          Age (min) Hardware Addr   Type   Interface
Internet 10.3.1.1                0   0018.19f3.f3e2 ARPA   BVI1
Internet 10.3.1.12               -   0000.0caa.8871 ARPA   BVI1
Internet 10.3.1.217              1   0024.d7e8.8624 ARPA   BVI1
Internet 10.3.1.250              2   0000.39a9.4fc6 ARPA   BVI1
Internet 192.168.99.1            -   001c.b1ec.0c62 ARPA   Vlan1
Router#ping 10.3.1.1

Sending 5, 100-byte ICMP Echos to 10.3.1.1, timeout is 2 seconds:

.....

Success rate is 0 percent (0/5) Sending 5, 100-byte ICMP Echos to 10.3.1.1, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)

Edison Ortiz · ‎03-03-2014

If you can't ping from the BVI interface to the local device, it's not a NAT issue.

Verify the ATM is working and the BVI interface is up/up.

Phil Bartlett · ‎03-03-2014

All interfaces seem to be up

*Mar 14 20:00:31.180: %SYS-5-CONFIG_I: Configured from console by consoleint

ATM0 is up, line protocol is up

Hardware is MPC ATMSAR (with Alcatel ADSL Module)

MTU 4470 bytes, sub MTU 4470, BW 852 Kbit/sec, DLY 430 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation ATM, loopback not set

Encapsulation(s): AAL5 AAL2, PVC mode

10 maximum active VCs, 1024 VCs per VP, 1 current VCCs

VC Auto Creation Disabled.

VC idle disconnect time: 300 seconds

Last input 00:00:00, output 00:00:00, output hang never

Last clearing of "show interface" counters never

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: Per VC Queueing

5 minute input rate 0 bits/sec, 1 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

2980 packets input, 393968 bytes, 0 no buffer

Received 716 broadcasts, 0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort

957 packets output, 45411 bytes, 0 underruns

0 output errors, 0 collisions, 2 interface resets

97 unknown protocol drops

0 output buffer failures, 0 output buffers swapped out

ATM0.1 is up, line protocol is up

Hardware is MPC ATMSAR (with Alcatel ADSL Module)

Description: DSL Link

MTU 4470 bytes, BW 852 Kbit/sec, DLY 430 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation ATM

2391 packets input, 362274 bytes

964 packets output, 45740 bytes

0 OAM cells input, 0 OAM cells output

AAL5 CRC errors : 0

AAL5 SAR Timeouts : 0

AAL5 Oversized SDUs : 0

ARP type: ARPA, ARP Timeout 04:00:00

Last clearing of "show interface" counters never

BVI1 is up, line protocol is up

Hardware is BVI, address is 0000.0c1d.a3bd (bia 001a.e3b0.4e69)

Internet address is 10.3.1.12/24

MTU 4470 bytes, BW 4608 Kbit/sec, DLY 5000 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation ARPA, loopback not set

ARP type: ARPA, ARP Timeout 04:00:00

Last input never, output never, output hang never

Last clearing of "show interface" counters never

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue: 0/0 (size/max)

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

315 packets input, 26026 bytes, 0 no buffer

Received 0 broadcasts, 0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort

31 packets output, 1860 bytes, 0 underruns

0 output errors, 0 collisions, 0 interface resets

0 unknown protocol drops

0 output buffer failures, 0 output buffers swapped out

Router#sh arp

Protocol Address Age (min) Hardware Addr Type Interface

Internet 10.3.1.12 - 0000.0c1d.a3bd ARPA BVI1

Internet 10.3.1.217 1 0024.d7e8.8624 ARPA BVI1

Internet 192.168.99.1 - 001a.e3b0.4e69 ARPA Vlan1

*Mar 14 20:00:31.180: %SYS-5-CONFIG_I: Configured from console by consoleint
ATM0 is up, line protocol is up
Hardware is MPC ATMSAR (with Alcatel ADSL Module)
MTU 4470 bytes, sub MTU 4470, BW 852 Kbit/sec, DLY 430 usec,
     reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ATM, loopback not set
Encapsulation(s): AAL5 AAL2, PVC mode
10 maximum active VCs, 1024 VCs per VP, 1 current VCCs
VC Auto Creation Disabled.
VC idle disconnect time: 300 seconds
Last input 00:00:00, output 00:00:00, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: Per VC Queueing
5 minute input rate 0 bits/sec, 1 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
     2980 packets input, 393968 bytes, 0 no buffer
     Received 716 broadcasts, 0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     957 packets output, 45411 bytes, 0 underruns
     0 output errors, 0 collisions, 2 interface resets
     97 unknown protocol drops
     0 output buffer failures, 0 output buffers swapped out
ATM0.1 is up, line protocol is up
Hardware is MPC ATMSAR (with Alcatel ADSL Module)
Description: DSL Link
MTU 4470 bytes, BW 852 Kbit/sec, DLY 430 usec,
     reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ATM
     2391 packets input, 362274 bytes
     964 packets output, 45740 bytes
     0 OAM cells input, 0 OAM cells output
AAL5 CRC errors : 0
AAL5 SAR Timeouts : 0
AAL5 Oversized SDUs : 0
ARP type: ARPA, ARP Timeout 04:00:00
Last clearing of "show interface" counters never
BVI1 is up, line protocol is up
Hardware is BVI, address is 0000.0c1d.a3bd (bia 001a.e3b0.4e69)
Internet address is 10.3.1.12/24
MTU 4470 bytes, BW 4608 Kbit/sec, DLY 5000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output never, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/0 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
     315 packets input, 26026 bytes, 0 no buffer
     Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     31 packets output, 1860 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 unknown protocol drops
     0 output buffer failures, 0 output buffers swapped out

Traffic seems to be coming down but not going up. The ARP table is populated with MACS on the 10.3.1.x network

Router#sh arp
Protocol Address          Age (min) Hardware Addr   Type   Interface
Internet 10.3.1.12               -   0000.0c1d.a3bd ARPA   BVI1
Internet 10.3.1.217              1   0024.d7e8.8624 ARPA   BVI1
Internet 192.168.99.1            -   001a.e3b0.4e69 ARPA   Vlan1

Edison Ortiz · ‎03-04-2014

.217 keeps showing up in your ARP table. Have you identified this device?

Can you ping it? You need to verify why .1 is not responding to pings.

If that device is owned by the ISP, you need to work with them.