ADSL 877W issue. ATM interface keeps dropping
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
11-21-2007 01:46 AM - edited 03-03-2019 07:37 PM
Hello,
I have a little problem. I configured an ADSL 877W. After it was plugged in, the dialer interface negotiated its IP address ok, but after a few minutes, the atm interface started flapping. It flapped a couple of times, then i lost the IP address. It never picked up an IP address again. I did a couple of debugs, and i couldnt find any errors. The router was replaced with a netgear router, and it worked fine. I replaced the ADSL 877W with a brand new one, and i still experienced the same issue. Please help. My config is as follows:
EASTERN_REGION#sh run
!
ip cef
ip dhcp excluded-address 192.168.10.1 192.168.10.20
!
ip dhcp pool XXX_POOL
network 192.168.10.0 255.255.255.0
dns-server 192.168.10.1
default-router 192.168.10.1
domain-name fmb.co.uk
!
!
ip domain name yourdomain.com
ip name-server yy.yy.yy.yy
ip name-server xx.xx.xx.xx
!
!
crypto pki trustpoint TP-self-signed-978332037
enrollment selfsigned
subject-name cn=IOS-Self-Signed-Certificate-978332037
revocation-check none
rsakeypair TP-self-signed-978332037
!
!
crypto isakmp policy 10
hash md5
authentication pre-share
crypto isakmp key uqef23fr923fg address xx.xx.xx.xx
!
!
crypto ipsec transform-set headoffice esp-des esp-md5-hmac
!
crypto map headoffice 10 ipsec-isakmp
set peer xx.xx.xx.xx
set transform-set headoffice
match address 101
!
bridge irb
!
!
interface ATM0
no ip address
no ip redirects
no ip unreachables
no ip proxy-arp
ip route-cache flow
no atm ilmi-keepalive
pvc 0/38
encapsulation aal5mux ppp dialer
dialer pool-member 1
!
dsl operating-mode auto
dsl enable-training-log
!
interface FastEthernet0
!
interface FastEthernet1
!
interface FastEthernet2
!
interface FastEthernet3
!
interface Dot11Radio0
no ip address
no ip route-cache cef
no ip route-cache
!
encryption vlan 1 key 1 size 40bit 0 1234567890 transmit-key
encryption vlan 1 mode wep mandatory
!
ssid FMB_WLAN
vlan 1
authentication open
guest-mode
!
world-mode dot11d country GB both
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 Dot11Radio0.1
encapsulation dot1Q 1 native
no ip route-cache
no snmp trap link-status
bridge-group 1
bridge-group 1 subscriber-loop-control
bridge-group 1 spanning-disabled
bridge-group 1 block-unknown-source
no bridge-group 1 source-learning
no bridge-group 1 unicast-flooding
!
interface Vlan1
no ip address
ip tcp adjust-mss 1452
bridge-group 1
!
interface Dialer1
ip address negotiated
no ip redirects
no ip unreachables
no ip proxy-arp
ip mtu 1492
ip nat outside
ip virtual-reassembly
encapsulation ppp
ip route-cache flow
dialer pool 1
dialer-group 1
no cdp enable
ppp authentication chap pap callin
ppp chap hostname xx.xx.xxxx@lanz.broadband
ppp chap password 0 Change
crypto map headoffice
!
interface BVI1
ip address 192.168.10.1 255.255.255.0
ip nat inside
ip virtual-reassembly
ip tcp adjust-mss 1452
!
ip classless
ip route 0.0.0.0 0.0.0.0 Dialer1
!
ip http server
ip http access-class 23
ip http authentication local
ip http secure-server
ip http timeout-policy idle 60 life 86400 requests 10000
ip nat inside source list 102 interface Dialer1 overload
ip nat inside source route-map nonat interface Dialer1 overload
!
access-list 24 permit xx.xx.xx.xx
access-list 24 permit 192.168.0.0 0.0.255.255
access-list 23 permit xx.xx.xx.xx
access-list 23 permit 192.168.0.0 0.0.255.255
access-list 101 permit ip 192.168.10.0 0.0.0.255 192.168.250.0 0.0.0.255
access-list 102 deny ip 192.168.10.0 0.0.0.255 192.168.250.0 0.0.0.255
access-list 102 permit ip 192.168.10.0 0.0.0.255 any
dialer-list 1 protocol ip permit
route-map nonat permit 10
match ip address 102
!
!
control-plane
!
bridge 1 protocol ieee
bridge 1 route ip
!
line con 0
no modem enable
line aux 0
line vty 0 4
access-class 24 in
privilege level 15
password $$$$$$$
login
transport input telnet ssh
!
scheduler max-task-time 5000
end
- Labels:
-
Other Routing
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
11-21-2007 07:41 AM
how is your loop loss/line attenuation
issue a "show dsl interface atm0" and it should give you some info.
also what other debug options have you run?

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
12-13-2007 04:18 AM
If you haven't already, you could try upgrading the ADSL modem firmware on your router. There have been several ADSL inoperability issues with the 877s and certain DSLAMs so Cisco have released a few firmware upgrades.
If you go here, you can see the firware updates available:
ftp://ftp.cisco.com/pub/access/800/
I upgraded firmware on my 877s to 3.0.10 in the past and that resolved similar ADSL "training" issues for me and I see that there have been a couple more firmware updates released since then.
You can look at the readme files from the above FTP site for more details and the full installation process but basically, to upgrade the firmware:
Use "sh dsl int atm0" to identify current firmware
e.g. "FW Version: 2.542"
TFTP the new firmware file (e.g. adsl_alc_20190_3.0.10.bin) into the router's flash.
Rename the new file as "adsl_alc_20190.bin"
Reboot the router for the new firmware to take effect.
When the router comes back up, issue "sh dsl int atm0" again to confirm the router is using the new firmware
e.g. "FW Version: 3.010"
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
12-17-2007 09:13 AM
Hello
I too own a Cisco 877 adsl router and have noticed that the DSL connection drops about 5 times a day. I have contacted the ISP and they inform me that it is my device that is causing the reset. I have done some checking and tried the atm firmware upgrade but this has not resolved the problem. any ideas?
Modem Status: Showtime (DMTDSL_SHOWTIME)
DSL Mode: ITU G.992.1 (G.DMT) Annex A
Noise Margin: 0.5 dB 22.0 dB
Output Power: 20.0 dBm 12.5 dBm
Attenuation: 48.0 dB 24.0 dB
Activations: 4
Init FW: init_3.0.33_nobist.bin
Operation FW: AMR-3.0.033.bin
FW Source: external
FW Version: 3.0.33

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
12-17-2007 10:06 AM
Here's a few things you could try which might at least help to eliminate some possible causes (I'm assuming you're in the UK!)
1) if you're not already connecting from the master socket (e.g. if you're connecting from an extension), then try connecting via the master socket and disconnecting any other telephony equipment - see if that makes any difference?
2) replace your ADSL microfilter with a good quality "BT approved" one and see if that makes any difference?
3) try connecting to the special BT Test socket (assuming you have an NTE5 type socket) On the face plate of the NTE5 are two screws. If you unscrew them, the bottom half of the BT Master socket can be removed, and you'll see a standard sized BT socket. Connect your microfilter and router to this test socket and see if that makes a difference?
4) if you've got another router (even another vendor's router?) then connect that up and see if it makes a difference?
Hope that helps identify the cause somehow!
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
12-17-2007 10:57 AM
Out of interest does you wireless settings work in your config? I need to confgure my 877w to use wireless and are getting into some problems, so I thought I could work with yous as an example?
Thanks

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
12-17-2007 10:59 AM
What problems do you specifically have ?
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
12-18-2007 01:02 AM
Hello and ty for replying
Yes i do live in the UK.
I will try replacing the ADSL filter as i do have spares.
Also internal phone wiring is not the problem as when i moved into the house i removed all the wiring as it was very old. so from the box on the outside of my house which the bt line come into, it's a 1m distance to my study (aka box room) which terminates into the master socket. and thats it. 1m cable and 1 socket. the rest of the phones in the house use wireless from the base station. Anyways probably a little too much info :)
i have only noticed this drop since upgrading to the cisco 877 from my many netgears.
i do live far from the exchange, about 1.5miles hense the high Attenuation.
Capacity Used: 100% 53%
Noise Margin: 8.0 dB 22.0 dB
Output Power: 20.0 dBm 12.5 dBm
Attenuation: 48.0 dB 24.0 dB
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
12-18-2007 01:14 AM
update:
i placed a "debug atm state" last night and captured the following.
Dec 18 08:43:55.288: Changing vc 0/38vc-state to ATM_VC_SHUTTING_DOWN
Dec 18 08:43:55.288: Changing vc 0/38vc-state to ATM_VC_NOT_IN_SERVICE
Dec 18 08:43:56.256: %LINK-3-UPDOWN: Interface Virtual-Access2, changed state to down
Dec 18 08:43:56.256: %DIALER-6-UNBIND: Interface Vi2 unbound from profile Di0
Dec 18 08:43:57.255: %LINEPROTO-5-UPDOWN: Line protocol on Interface Virtual-Access2, changed state to down
Dec 18 08:43:57.287: %LINK-3-UPDOWN: Interface ATM0, changed state to down
Dec 18 08:43:58.287: %LINEPROTO-5-UPDOWN: Line protocol on Interface ATM0, changed state to down
Dec 18 08:44:17.154: %LINK-3-UPDOWN: Interface ATM0, changed state to up
Dec 18 08:44:18.153: %LINEPROTO-5-UPDOWN: Line protocol on Interface ATM0, changed state to up
Dec 18 08:44:21.072: Changing vc 0/38 vc-state to ATM_VC_ESTABLISHING_VC
Dec 18 08:44:21.072: Changing vc 0/38 vc-state to ATM_VC_NOT_VERIFIED
Dec 18 08:44:21.072: Changing vc 0/38 vc-state to ATM_VC_UP
Dec 18 08:44:22.060: %LINK-3-UPDOWN: Interface Virtual-Access2, changed state to up
Dec 18 08:44:22.060: %DIALER-6-BIND: Interface Vi2 bound to profile Di0
Dec 18 08:44:28.314: %LINEPROTO-5-UPDOWN: Line protocol on Interface Virtual-Access2, changed state to up
not very detailed but i could setup a syslog server if capturing a more detailed debug is required.
Regards
Dean.

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
12-18-2007 02:16 AM
Yes, I think it would probably be useful to capture as much debug output as you can (don't know if I'd be able to help much with any analysis personally but I'm sure someone on here would!)
There's a utility here for analysing dsl debug output which might be of use to you though:
http://cosi-nms.sourceforge.net/cgitools/dsl_show/
Also, this is perhaps clutching at straws, but I do recall people in the past having stability issues with ADSL and 800 series routers and resolving it by changing "dsl operating-mode auto" under the ATM0 interface to "dsl operating-mode ansi-dmt"
You may have tried that already though if you've browsed through these forums for similar issues. I've never had to do that myself as the firmware upgrade has usually resolved the situation for me!
Also, if you still have one of your old netgear routers handy that you could swap for the 877 temporarily then you could see if it exhibits the same issues? (Just a point of note, I've found the older Cisco 837 routers seemed to be far more stable on ADSL Max connections than the 877s have been, for some reason?)
These sort of issues are usually quite hard to troubleshoot unfortunately - particularly as ISPs normally try to fob off faults on the end user's kit without doing much in the way of detailed investigation. So its just a case of doing as much as you can to eliminate possible causes I think!
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
12-18-2007 02:37 AM
Hello,
i hadn't actually tied the operating mode adjustment. i have however just changed it from auto to ansi-dmt (please see attached config)
interface ATM0
no ip address
no ip unreachables
ip route-cache flow
logging event subif-link-status
no atm ilmi-keepalive
pvc 0/38
encapsulation aal5mux ppp dialer
dialer pool-member 1
!
dsl operating-mode ansi-dmt
end
the interface is now back up and working so i will enable the debugging tonight once i have a syslog server setup.
i will try the utility you refered to and see what results that turns up.
thank you for your reply and i will update soon.
Regards
Dean.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
12-18-2007 06:01 AM
update:
since changing the dsl mode i have had 35 resets in 5hrs so i will change the mode back to auto. see show dsl int atm0
Modem Status: Showtime (DMTDSL_SHOWTIME)
DSL Mode: ANSI T1.413
ANSI Issue/rev: 2/1 2/1
Vendor ID: 0x003A 0x0004
Chip ID: C196 (0)
DFE BOM: DFE3.0 Annex A (1)
Capacity Used: 99% 53%
Noise Margin: 14.5 dB 23.0 dB
Output Power: 20.0 dBm 12.5 dBm
Attenuation: 48.0 dB 24.0 dB
Defect Status: None None
Last Fail Code: None
Watchdog Counter: 0x29
Watchdog Resets: 0
Selftest Result: 0x00
Subfunction: 0x00
Interrupts: 8312 (0 spurious)
PHY Access Err: 0
Activations: 35
changing the mode back to auto and it has now negociated the following
DSL Mode: ITU G.992.1 (G.DMT) Annex A
i will monitor this for 5 hrs and report back the number of resets.
Dean.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
12-23-2007 10:04 AM
Out of interest I take your wireless settings work nicely? I would like to use yours as a template for mine, changing the obvious parts to suit me.
Thanks
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
12-24-2007 04:09 PM
Try this one.
Before try delete:
interface Dialer1
interface ATM0
dsl operating-mode auto
dsl enable-training-log
After:
interface ATM0
no ip address
no ip redirects
no ip unreachables
no ip proxy-arp
ip route-cache flow
no atm ilmi-keepalive
dsl operating-mode auto
!
interface ATM0.1 point-to-point
no snmp trap link-status
pvc 0/38
encapsulation aal5mux ppp dialer
dialer pool-member 1
!
interface Dialer0
ip address negotiated
no ip redirects
no ip unreachables
no ip proxy-arp
ip nat outside
ip virtual-reassembly
encapsulation ppp
ip route-cache flow
dialer pool 1
dialer-group 1
no cdp enable
ppp authentication chap pap callin
ppp chap hostname xxxxxxxx@xxxxxx.xxxx
ppp chap password xxxxxxxxxxxxx
ppp pap sent-username xxxxxxxx@xxxxxx.xxxx password xxxxxxxxxxxxxxxxxxxxxx
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
01-21-2008 05:23 AM
Hello all
I'm finally back home and will now be able to continue this as it is an ongoing problem.
I have the syslog server running so i hope to get some output on the next drop. A quick question on the last post, how would creating a sub interface help with this problem?
Thanks
Dean.
