Buy or Renew
Buy or Renew
cancel
Turn on suggestions
Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.
Showing results for 
Search instead for 
Did you mean: 
cancel
Start a conversation
903
Views
0
Helpful
7
Replies

Dial Backup question

techeleccmd1775
Level 1
Level 1

‎10-14-2011 10:21 AM - edited ‎03-04-2019 01:56 PM

I am trying to configure dial backup on a WAN router so that when the WAN interface goes down,

the router will initiate a dial back up using a modem connected to a serial interface off of this router. Here is part of the config. When the WAN interface is shutdown, I can see the async 5 interface transition from the standby state to down… It is never trying to dial..

Should the modem be connected to the aux port and not the serial interface?

Help me please…

chat-script backup "" "atdt\T" TIMEOUT 60 CONNECT\C

interface FastEthernet0

backup interface async5

ip address 172.28.155.51 255.255.255.0

speed auto

interface Serial1

no ip address

interface Async5

ip address 192.168.251.214 255.255.255.0

encapsulation ppp

keepalive 10

dialer in-band

dialer idle-timeout 1000 either

dialer enable-timeout 6

dialer map ip 192.168.251.1 name RameyGO broadcast 8912360

dialer-group 1

async default routing

async mode interactive

no peer default ip address

ppp authentication chap callin

!

Labels:
0 Helpful
7 Replies 7

Richard Burts
Hall of Fame
Hall of Fame

‎10-16-2011 07:16 PM

The biggest problem in what you describe is how you are attempting to test dial backup. If you shut down the primary interface then it will not initiate the backup. IOS interprets the shutdown command as your desire to disable the interface and it will not initiate backup for this. To test backup interface you need to produce a real failure of the interface (I suggest a physical disconnect of the interface as the easiest and most reliable test).

I note a few other issues or comments about potential issues about what you are trying to accomplish:

- your post indicates that the modem is on a serial interface and the partial config posted has a serial interface. But the dialer configuration is on an async interface. Is there something linking the async interface and the serial interface that is not show in the posted partial config?

- backup interface is activated if the primary interface goes line protocol down. But the primary interface is a FastEthernet. Ethernet interfaces will frequently lose connectivity to other devices connected over Ethernet but the Ethernet interface remains line protocol up. You may need some tracking or some IP SLA configuration to check on connectivity to get the dial backup to work.

HTH

Rick

HTH

Rick
0 Helpful

techeleccmd1775
Level 1
Level 1
In response to Richard Burts

‎10-18-2011 06:38 AM

Here is my config (the dial backup parts). When I unplug the fa0 interface, I am still not getting any modem dialout. Below the config is the logs I am getting on the router that is trying to dialout.

aaa authentication ppp default local

username RameyGO secret 5 $1$hJj8$qSNFoN9sR24RSTVzv7CTK.

chat-script backup "" "atdt\T" TIMEOUT 60 CONNECT\C

interface FastEthernet0

backup interface Serial0

ip address 172.28.155.51 255.255.255.0

speed auto

!

interface Serial0

physical-layer async

ip address 192.168.251.214 255.255.255.0

encapsulation ppp

dialer in-band

dialer map ip 192.168.251.1 name RameyGO modem-script backup 8912360

dialer-group 1

async mode dedicated

no peer default ip address

no fair-queue

ppp authentication chap callin

dialer-list 1 protocol ip permit

line 1

script dialer backup

modem InOut

modem autoconfigure type usr_sportster

transport input all

speed 115200

flowcontrol hardware

Log:

25:35.108: Se0 LCP: O CONFREQ [REQsent] id 135 len 25

Oct 18 08:25:35.108: Se0 LCP:    ACCM 0x000A0000 (0x0206000A0000)

Oct 18 08:25:35.108: Se0 LCP:    AuthProto CHAP (0x0305C22305)

Oct 18 08:25:35.108: Se0 LCP:    MagicNumber 0x2FFC866B (0x05062FFC866B)

Oct 18 08:25:35.108: Se0 LCP:    PFC (0x0702)

Oct 18 08:25:35.108: Se0 LCP:    ACFC (0x0802)

Oct 18 08:25:35.112: Se0 EVT: Packet 0 0x80F12980

Oct 18 08:25:35.116: Se0 LCP: I CONFREQ [REQsent] id 135 len 25

Oct 18 08:25:35.116: Se0 LCP:    ACCM 0x000A0000 (0x0206000A0000)

Oct 18 08:25:35.116: Se0 LCP:    AuthProto CHAP (0x0305C22305)

Oct 18 08:25:35.116: Se0 LCP:    MagicNumber 0x2FFC866B (0x05062FFC866B)

Oct 18 08:25:35.116: Se0 LCP:    PFC (0x0702)

Oct 18 08:25:35.116: Se0 LCP:    ACFC (0x0802)

Oct 18 08:25:35.116: Se0 LCP: O CONFREJ [REQsent] id 135 len 10

Oct 18 08:25:35.116: Se0 LCP:    MagicNumber 0x2FFC866B (0x05062FFC866B)

Oct 18 08:25:35.120: Se0 EVT: Packet 0 0x80F0CD98

Oct 18 08:25:35.120: Se0 LCP: I CONFREJ [REQsent] id 135 len 10

Oct 18 08:25:35.120: Se0 LCP:    MagicNumber 0x2FFC866B (0x05062FFC866B)

Oct 18 08:25:35.120: Se0 LCP: O CONFREQ [REQsent] id 136 len 19

Oct 18 08:25:35.120: Se0 LCP:    ACCM 0x000A0000 (0x0206000A0000)

Oct 18 08:25:35.124: Se0 LCP:    AuthProto CHAP (0x0305C22305)

Oct 18 08:25:35.124: Se0 LCP:    PFC (0x0702)

Oct 18 08:25:35.124: Se0 LCP:    ACFC (0x0802)

Oct 18 08:25:35.128: Se0 EVT: Packet 0 0x80ED6E14

Oct 18 08:25:35.128: Se0 LCP: I CONFREQ [REQsent] id 136 len 19

Oct 18 08:25:35.128: Se0 LCP:    ACCM 0x000A0000 (0x0206000A0000)

Oct 18 08:25:35.128: Se0 LCP:    AuthProto CHAP (0x0305C22305)

Oct 18 08:25:35.128: Se0 LCP:    PFC (0x0702)

Oct 18 08:25:35.128: Se0 LCP:    ACFC (0x0802)

Oct 18 08:25:35.132: Se0 LCP: O CONFACK [REQsent] id 136 len 19

Oct 18 08:25:35.132: Se0 LCP:    ACCM 0x000A0000 (0x0206000A0000)

Oct 18 08:25:35.132: Se0 LCP:    AuthProto CHAP (0x0305C22305)

Oct 18 08:25:35.132: Se0 LCP:    PFC (0x0702)

Oct 18 08:25:35.132: Se0 LCP:    ACFC (0x0802)

Oct 18 08:25:35.136: Se0 EVT: Packet 0 0x80CBC294

Oct 18 08:25:35.136: Se0 LCP: I CONFACK [ACKsent] id 136 len 19

Oct 18 08:25:35.136: Se0 LCP:    ACCM 0x000A0000 (0x0206000A0000)

Oct 18 08:25:35.136: Se0 LCP:    AuthProto CHAP (0x0305C22305)

Oct 18 08:25:35.136: Se0 LCP:    PFC (0x0702)

Oct 18 08:25:35.136: Se0 LCP:    ACFC (0x0802)

Oct 18 08:25:35.136: Se0 LCP: State is Open

Oct 18 08:25:35.140: Se0 PPP: Phase is AUTHENTICATING, by both

Oct 18 08:25:35.140: Se0 CHAP: O CHALLENGE id 56 len 29 from "National"

Oct 18 08:25:35.144: Se0 EVT: Auth Packet 0 0x80CBBD94

Oct 18 08:25:35.144: Se0 CHAP: I CHALLENGE id 56 len 29 from "National"

Oct 18 08:25:35.144: Se0 CHAP: Ignoring Challenge with local name

Oct 18 08:25:45.124: Se0 AUTH: Timeout 1

Oct 18 08:25:45.124: Se0 CHAP: O CHALLENGE id 57 len 29 from "National"

Oct 18 08:25:45.128: Se0 EVT: Auth Packet 0 0x80EC1604

Oct 18 08:25:45.128: Se0 CHAP: I CHALLENGE id 57 len 29 from "National"

Oct 18 08:25:45.128: Se0 CHAP: Ignoring Challenge with local name

Oct 18 08:25:55.140: Se0 AUTH: Timeout 2

Oct 18 08:25:55.140: Se0 CHAP: O CHALLENGE id 58 len 29 from "National"

Oct 18 08:25:55.144: Se0 EVT: Auth Packet 0 0x80F0F7E0

Oct 18 08:25:55.144: Se0 CHAP: I CHALLENGE id 58 len 29 from "National"

Oct 18 08:25:55.144: Se0 CHAP: Ignoring Challenge with local name

Oct 18 08:26:05.156: Se0 AUTH: Timeout 3

Oct 18 08:26:05.156: Se0 CHAP: O CHALLENGE id 59 len 29 from "National"

Oct 18 08:26:05.160: Se0 EVT: Auth Packet 0 0x80E63F30

Oct 18 08:26:05.160: Se0 CHAP: I CHALLENGE id 59 len 29 from "National"

Oct 18 08:26:05.160: Se0 CHAP: Ignoring Challenge with local name

Oct 18 08:26:12.356: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0, changed state to up

Oct 18 08:26:12.360: Se0 EVT: Cstate 0 0x0

Oct 18 08:26:14.360: %LINK-5-CHANGED: Interface Serial0, changed state to standby mode

Oct 18 08:26:14.360: Se0 EVT: Cstate 6 0x0

Oct 18 08:26:14.360: Se0 PPP: Phase is TERMINATING

--More--

0 Helpful

Richard Burts
Hall of Fame
Hall of Fame
In response to techeleccmd1775

‎10-18-2011 10:19 AM

The logs provide helpful information. In particular I see several occurrences of this series of messages

Oct 18 08:25:35.144: Se0 CHAP: I CHALLENGE id 56 len 29 from "National"

Oct 18 08:25:35.144: Se0 CHAP: Ignoring Challenge with local name

Oct 18 08:25:45.124: Se0 AUTH: Timeout 1

So you receive a challenge from the other device and you ignore the challenge. If you ignore the challenge and do not respond then obviously authentication is going to fail.

Can you post the configuration from the device that you are attempting to connect to? It would help to see how they are configured and what they are sending that your router does not like.

HTH

Rick

HTH

Rick
0 Helpful

techeleccmd1775
Level 1
Level 1
In response to Richard Burts

‎10-18-2011 10:24 AM

But I don't think this device is ever dialing out.....

0 Helpful

Richard Burts
Hall of Fame
Hall of Fame
In response to techeleccmd1775

‎10-18-2011 10:39 AM

The router is using PPP encapsulation on the line to dial. PPP performs LCP (Link Control Protocol) negotiation to prepare for dialing and part of the negotiation is to authenticate. The authentication is failing. So you are quite correct that the router is not dialing. It is not dialing because the negotiation to prepare the line is failing. Until you fix the authentication problem the router will not be able to dial.

HTH

Rick

HTH

Rick
0 Helpful

techeleccmd1775
Level 1
Level 1
In response to Richard Burts

‎10-18-2011 11:06 AM

So what is it trying to authenticate to, itself??? It can't authenticate to the headend router if it hasn't yet dialed in...

I don't understand what it is trying to authenticate to...

Thanks

0 Helpful

techeleccmd1775
Level 1
Level 1
In response to Richard Burts

‎10-19-2011 07:54 AM

Help...

0 Helpful
Customers Also Viewed These Support Documents
Review Cisco Networking for a $25 gift card