Hello

My name is brayan and i am from colombia

I want to help you

If you want you can to send me the router`s configuration. I wil help you

Bye

Hi Brayan,

Thanks for replying to my post. I guess you are on Telmex so that you can help me. I used my 877 box with different ISPs and did not have any problems. I have my router running for 10 hours now without any disconecctions so fingers crossed. Can you analyse ADSL line and signal quality like noise margin, power level or attenuation? I thought this may be the case but those figures change from time to time and I found a little bit info how to interpret them. Can you also anayse debug atm events or debug atm errors? I spet hours on doing that and reseraching for similar problems. The one thing I know is that the 2Wire broadband router provided by Telmex works fine. I also noticed Telmex changes adsl modulation from ADSL2+ to ANSI T. 413 from time to time but my cisco router seems to be liking more if I set my dsl modulation to adsl2+ rather than auto.

I am going to paste here just interesting bits and pieces for you to look at. Note that even if I use subinterface ATM0. 1 point-to-point this does not help, I noticed it makes it even worse on some occasions. At the moment I have pppoe running of ATM0. I also tried aal5snap as well as aal5mux encapsulations but not much help. I found someone can run the atm on pvc 8/81, 8/80 or 8/88 values but I have not tried.

Hope that gives you view on my problem and hope you can help me. Many thanks. Remi

Interface ATM0
 mtu 1500
 no ip address
 no ip redirects
 no ip unreachables
 no ip proxy-arp
 no atm ilmi-keepalive
 pvc 8/81
  pppoe-client dial-pool-number 1
 !        
 dsl operating-mode adsl2+
 dsl enable-training-log

!

Interface Dialer1
 description ***Outside Network Perimiter***
 mtu 1492 
 ip address negotiated
 ip access-group ... In
 no ip redirects
 no ip unreachables
 no ip proxy-arp
 ip nat outside
 ip inspect ... In
 ip virtual-reassembly
 encapsulation ppp
 dialer pool 1
 dialer-group 1
 no cdp enable
 ppp authentication pap callin
 ppp pap sent-username ... Password ...
 

Hello

I am going to study your configuration and to search in cisco page for answer you the questions. One thing i can not see the information about noise... So on becouse i am in colombia.

I thing that the problem can be that the transmition power from telmex can be small. Then your router is flapping.

Bye

Hi Bryan,

Thank you for responding quickly. You may be right however I thought the same when I was observing the power levels for downstream as well as upstream. Please find below the most up to date values on my Cisco box as well as for 2Wire broadband router from last night. You see, power level on the upstream has dropped twice over the night on the cisco box however to make it sound more paradox when my cisco router was running for over 3 weeks the power level on the upstream was actually              -2 dBm (negative value).

Once again thank you Brayan for your help and searching cure to my problem and let me know if you need anything else. By the way, you work in Cisco environment and routers/switches? Remi

Cisco - sh dsl int atm0 (yesterday 29 April 8:45pm)

Noise Margin:    18. 5 dB                         35. 0 dB
Output Power:    19. 0 dBm                         12 dBm
Attenuation:     28 dB                         12. 0 dB

Cisco - sh dsl int atm0 (today 30 April 9:00am)

Alcatel 20190 chipset information
                ATU-R (DS)                      ATU-C (US)
Modem Status:    Showtime (DMTDSL_SHOWTIME)
DSL Mode:        ITU G.992.5 (ADSL2+) Annex A
ITU STD NUM:     0x03                            0x2
Chip Vendor ID:  "STMI"                          "BDCM"
Chip Vendor Specific:  0x0000                    0x6193
Chip Vendor Country:   0x0F                      0xB5
Modem Vendor ID: "CSCO"                          "    "
Modem Vendor Specific: 0x0000                    0x0000
Modem Vendor Country:  0xB5                      0x00
Serial Number Near:    FHK111415CR
Serial Number Far:    
Modem Version Near:    12. 4(11)T1
Modem Version Far:    
Capacity Used:   19%                             21%
Noise Margin:    19. 0 dB                         35. 0 dB
Output Power:    19. 0 dBm                         5. 5 dBm
Attenuation:     28. 5 dB                         12. 0 dB
Defect Status:   None                            None                       
Last Fail Code:  None
Watchdog Counter: 0x97
Watchdog Resets: 0
Selftest Result: 0x00
Subfunction:     0x00
Interrupts:      15780 (0 spurious)
PHY Access Err:  0
Activations:     2
LED Status:      ON
LED On Time:     100
LED Off Time:    100
Init FW:         init_3.0.33_nobist. Bin
Operation FW:    AMR-3.0.033. Bin
FW Source:       external
FW Version:      3.0.33

                 DS Channel1      DS Channel0   US Channel1       US Channel0
Speed (kbps):             0             2048             0               253
Cells:                    0          4003382             0          25793999
Reed-Solomon EC:          0                0             0                 0
CRC Errors:               0              324             0                 0
Header Errors:            0              294             0                 0
Total BER:                0E-0           9957E-9
Leakage Average BER:      0E-0           3680E-9
Interleave Delay:         0                4             0                16

2WIRE broadband router provided by Telmex

Noise Margin:    16. 2 dB                         33. 2 dB
Output Power:    15. 7 dBm                         11. 6 dBm
Attenuation:     28. 7 dB                         13. 0 dB

Hi Bryan,

It"s me again. Following the adsl details in my last message look at the latest values on cisco box. What do you think about that? Saludos, Remi

Capacity Used:   19%                             21%
Noise Margin:    18. 5 dB                         35. 0 dB
Output Power:    19. 0 dBm                        -1. 0 dBm
Attenuation:     28. 5 dB                         12. 0 dB

Hi Brayan,

Thanks for your email. I am CCNP as well as CCDP and did a quite deep investigation on the problem. I had this router working in London, UK and have no idea why I am having problems here with Telmex. It seems like they have lots of strange things going on...

Anyway, for the moment its OK, router running for over 20 hours now without problems. When the values change I"ll let you know. In the meantime in case you came accross any good interpretations of the values I sent you before you are welcome to make any suggestions.

Once again thanks for looking into this problem with me.

Cheers,

Remi

Hi Brayan,

I achieved my CCDP in London, England. First I went for CCNP and as you 2 of the exams - switching and routing overlap for CCNP and CCDP so after getting my CCNP I only had to take one exam ARCH to become CCDP. I can say that both exams CCDA as well ARCH are quite difficult. I also prepared myself for the exams with my own Cisco equipment. Now I am studying towards achieving CCVP and later CCSP before going for CCIE :-). Good luck with CCDP.

Regards,

Remi

Hey like you are ccnp i wnt to ask you smething

Can you to help me?

Hi Brayan,

Thanks for your email and I"ll try to help wherever I can. My Spanish is still poor so I used google translator to get everything you explained the problem. Well, can we trust google? :-)

From what I understood you try to enable dhcp snooping on the switch to prevent dhcp spoofing on a lan or vlan by a potential attacker who could use his computer as a dhcp server and roll-out a man-in-the-middle attack. Well, you also say that after enabling dhcp snooping globally (all the porst are unstrusted by default) and then you specify the uplink ports and the ports where dhcp server is attacheed as trusted, the clients still get IP addresses assigned by... I think here you meant dhcp server on trusted port, is that right? Your commands issues on the switch look sufficient to enable the scenario above however you may be missing the point of dhcp snooping here. The purpose of dhcp snooping is to prevent dhcp server response packet like DHCPOFFER, DHCPACK on untrusted interfaces, so no clients could use their machines as dhcp server. The clients on unstrusted interfaces still get IP addresses  assigned by a dhcp server on trusted port, bu the clients can only initialize dhcp request or answer the server. Also it would be wise to set ip dhcp snooping limit rate  rate to prevent dhcp ip addresses starvation, cisco recommends to use here 100 as a value.

Hope this helps and I am sorry if I did not get everything you said. You may already know everything what I said here :-). What to remember is trusted interfaces enable dhcp servers to answer the dhcp requests and unstrusted interfaces will prevent use a client machine as a dhcp server. Try to configure one of your client machines as dhcp server and attach it to unstrusted port see if other machine would get ip address from this spoofed dhcp server on a client machine. Let me know how it went.

Best of luck,

Remi

Hi Brayan,

To take CCDA - ARCH exam you don"t really need to go to a school or some kind of training center. It"s lots of theory, no configurations so that with soem good material to study and exam preparation you can do it yourself. Best if you could take your CCNP first so that you would have switching and routing already done for CCDP as those 2 exams overlap.

Best of luck,

Remi

Gracias por  tu respuesta. Pero la verdad no me aclarate demasiado. Porque no funciona mi configuracion. Porque puertos untrusted pueden asignar ip a los demas?

Falta algun comando

En cuanto a la certificacion  de routin y switching ya las tengo. Pero ccda no es muy dificil? O con el conocimiento de ccnp ya soy lo suficicntemente capas para prepararme por mi mismo?

Hello

Do you have pdf about CCDA o CCNP?

Can you give me this information?

Hola, alguien me puede decir cual es el nombre de usuario y la contrasena q lleva por defecto un router cisco serie 800? Gracias.

Bueno remi tienes que checar bien, la configuracion de los cables que estas itulizando si es categoria A o B y tambien debes de checar tus configuracion de router, con este comando "show running-config"

Usuario: admin
Passwd: cisco