No protocol pppoe command?

ciscolover · ‎01-02-2013

Hi all¡¡

I'm trying to configure an Cisco 1841 with IOS 12.4 to an FTTH conection.

I would configure PPOE protocol in the vpdn-group 1 but I can't see this option in the command line ¡¡¡

Router(config-vpdn-req-in)#protocol ?

l2tp Use L2TP

I have read about the command "bba-group pppoe global" but i'm not sure if it has the same result. It's valid?

How can I use the bba-group pppoe global¿? I need to use it with a virtual template?

Thanks '¡¡¡¡

Peter Paluch · ‎01-02-2013

Hello,

What exactly are you trying to configure - do you want to configure a PPPoE client or a PPPoE access concentrator?

Best regards,

Peter

ciscolover · ‎01-02-2013

Hi Peter,

I'm not an expert confiuring PPPoe on Cisco Routers. I have a comtrend router conected to ONT and I want to change it and use a Cisco 1841 router.

I think its a PPPOE client of the ISP and not a PPPOE concentrator. I have read some examples and all the examples talk about the comand "protocol ppoe" under de vpdn-group. In my router I can't include this command.

Some people talk about the command bba-group global ppoe, i think it is similar, but I'm not sure how to use it because I cannot find examples.

thanks ¡¡¡ I speak bad englis

Peter Paluch · ‎01-02-2013

Hello,

Do not worry about your English, it's okay!

So I assume you simply want to configure your router to access internet using PPPoE. Is that right? In that case, you do not need any of the VPDN or bba-group stuff and you should in fact remove it completely from your router.

The configuration of the basic PPPoE access would be as follows (take this as an example):

interface FastEthernet0/0

description => Interface towards the ONT <=

no ip address

pppoe-client dial-pool-number 1

no shutdown

!

interface Dialer1

encapsulation ppp

ip address negotiated

dialer pool 1

ppp chap hostname login@yourisp.com

ppp chap password YourPPPoEPassword

Please note that this configuration lacks many other parts that are necessary, such as NAT. If you would like me to include these then I would need to know more about your existing IP addressing, how is the 1841 connected to your network, etc.

Best regards,

Peter

ciscolover · ‎01-02-2013

Hi Peter and thanks ¡¡

I know how to configure nat, etc. No problem.

But if only you need to configure like your example, why in the link http://www.dslreports.com/faq/8199 uses vpdn-group?

And I have found another example(in spanish) and it talks exactly about my FTTH conection with a Cisco Router. It uses bba-group. I write you the Dialer1 interface. I have found 2 commands you don't include in your example(other than nat etc),

interface Dialer1

ip address negotiated

ip nat outside

ip nat enable

ip virtual-reassembly in

encapsulation ppp

dialer pool 1

dialer-group 1

ppp chap hostname XXXXXXXXXX

ppp chap password 0 adslppp

no cdp enable

hold-queue 224 in

Could you explain me why it uses dialer-group 1 etc. Tomorrow I go to try your config...

Peter Paluch · ‎01-02-2013

Hello,

But if only you need to configure like your example, why in the link http://www.dslreports.com/faq/8199 uses vpdn-group?

I believe that the article showed an older, obsolete approach of configuring the PPPoE client access. The way I have shown here is the way used in today's IOS versions. The VPDN is most often used if you need to perform tunneling of PPP frames over L2TP.

Regarding the configuration snippet you have posted:

ip virtual-reassembly in

This is a command that is usually inserted automatically by IOS. It allows the IOS to keep track of packet fragments that all belong to a single original unfragmented IP packet. This allows them, for example, to pass through firewall as if the packet was unfragmented. Keep in mind that if, for example, an IP packet containing a TCP segment was fragmented, the TCP header would be located only in the first fragment. The remaining fragments have only the IP header and would therefore not be appropriately matched by those entries in the firewall that look for TCP segments. This virtual reassembly function allows the IOS to keep enough information about packets to recognize whether a sequence of fragmented packets comes from a single unfragmented packet, and apply the same action to the 2nd, 3rd, ... last fragment that was also applied to the 1st fragment - just as if the packet was unfragmented.

dialer-group 1

This command is unnecessary on PPPoE. When dial-up technologies (analog modems, ISDN) were used, this command referred to a list of "interesting" traffic that caused the router to make a call. Traffic that was not considered "interesting" could pass through the Dialer interface once the session was established but it was not capable of causing the router to make a call or to keep the call active. However, the PPPoE is not about making calls anymore - it is always on, so there is no real point in defining an interesting traffic. This command is irrelevant for PPPoE.

Actually, I should correct my suggested Dialer1 configuration. I am missing two commands: ip mtu 1492 and ip tcp adjust-mss 1452. Both these commands configure the router to pass smaller IP packets through the Dialer interface and to adjust maximum TCP segment size of TCP sessions that are carried through the PPPoE session. The reason is that the PPP and PPPoE add additional 8 bytes, and the entire PPPoE+PPP+IP+L4+L5/6/7 must be carried in an Ethernet frame whose payload size still can not exceed 1500 bytes. Hence, we need to decrease the maximum IP and TCP size by 8. The resulting Dialer1 configuration would therefore be:

interface Dialer1
 encapsulation ppp
 ip address negotiated
 ip mtu 1492
 ip tcp adjust-mss 1452
 dialer pool 1
 ppp chap hostname login@yourisp.com
 ppp chap password YourPPPoEPassword

Feel welcome to ask further!

Best regards,

Peter

ciscolover · ‎01-03-2013

Hi Peter,

I have read than it's needed the conetion to the ONT tags with vlan 6 the frames. It's the data vlan of my ISP (the others are for TV and for phone).

One man configure this and it works :

-Interface fast ethernet 0/0 with encapsulation dot1q 6.

-Interface fast ethernet 0/0.6 with dialer group 1

But I have 2 problems:

-I can't write in Interface fast ethernet 0/0 encapsulation dot1q6.

-I can't associate dialer groups in interface fast ethernet 0/0.6

I have configure like this my router but it not works. Thanks for your help.

!

interface FastEthernet0/0

no ip address

no ip route-cache cef

no ip route-cache

duplex auto

speed auto

vlan-id dot1q 6

exit-vlan-config

!

pppoe enable

pppoe-client dial-pool-number 1

!

interface FastEthernet0/1

ip address 192.168.1.1 255.255.255.0

ip nat inside

ip virtual-reassembly

duplex auto

speed auto

no cdp enable

!

interface Dialer1

bandwidth 6192

ip address negotiated

ip mtu 1492

ip nat outside

ip virtual-reassembly

encapsulation ppp

ip tcp adjust-mss 1452

dialer pool 1

dialer-group 1

no cdp enable

ppp authentication chap pap callin

ppp chap hostname adslppp@telefonicanetpa

ppp chap password 0 adslppp

ppp pap sent-username adslppp@telefonicanetpa password 0 adslppp

max-reserved-bandwidth 100

!

ip route 0.0.0.0 0.0.0.0 Dialer1

!

ip nat inside source list 10 interface FastEthernet0/0 overload

!

access-list 10 permit 192.168.1.0 0.0.0.255

!

Peter Paluch · ‎01-03-2013

Hello,

I have read than it's needed the conetion to the ONT tags with vlan 6 the frames.

Are you sure you need to tag the frames? This is usually not requried to be done on the customer's side.

interface FastEthernet0/0

no ip address

no ip route-cache cef

no ip route-cache

duplex auto

speed auto

vlan-id dot1q 6

exit-vlan-config

!

pppoe enable

pppoe-client dial-pool-number 1

This configuration is not correct. The correct configuration is (you may paste it into your configuration, the default interface Fa0/0 will merely reset the Fa0/0 interface into the default configuration, removing all present comands):

default interface FastEthernet0/0

!

interface FastEthernet0/0

no shutdown

!

interface FastEthernet0/0.6

encapsulation dot1q 6

pppoe-client dial-pool-number 1

!

The rest of the configuration does not need to be changed.

In addition, the ppp authentication chap pap callin curently present on your Dialer interface is useless - please remove it. I have had lengthy discussions about the real purpose of this command in different threads:

https://supportforums.cisco.com/message/3424916#3424916

https://supportforums.cisco.com/message/3440088#3440088

Best regards,

Peter

ciscolover · ‎01-03-2013

Ok this works, thanks Peter.

1º)I have upgrade the firmware of my router to c1841-advipservicesk9-mz.124-24.T7.bin

After that I could configure encapsulation dot1q 6 and pppoe-client on subinterface 0/0.6

I will tryed to remove the chap pap callin but this works ¡¡¡

Regards.

Peter Paluch · ‎01-03-2013

Hello,

I am glad you got it running! Good work

Regarding the ppp authentication chap pap callin - yes, I know it currently works for you. That does not mean, though, that the command is required or reasonable. This one is not and it is not supposed to be present in your configuration at all. As I explained in the two other threads, this is a common myth that keeps repeating again and again.

Best regards,

Peter