What is the need of PPPoe? Why we
use PPPoe? Suppose a DSL user want to communicate with the Service Provider
(SP), that user must be authenticated
and we can do that by using PPPoe but we can do so by other ways also so what
is the real need for PPPoe to be used ? Many
things we can do with PPPoe like to verify the user before it comes on a link.
We can use OSPF or EIGRP for authentication but we need authentication before
the routing process starts. So if you want to do the authentication on the link
so PPPoe is the cool and right feature.
The DSL will dial ISP and will
ask that I want to dial up. The ISP will
reply that let me check your credential like username and password. The DSL
will say this is my username and password, the ISP will confirm through AAA or
any other server and will allow DSL to communicate to the internet using the
ISP backbone if request is successful.
In this lab to see the results we
will be using two Cisco-7200 routers where one will act as ISP and other will
act as DSL-Client.
First thing we need to do is the
bba (Broadband Access group)
SP-SERVER SIDE CONFIGURATION
SP-Server (config)# bba-group
pppoe TESTGROUP
SP-Server (config-bba-group)# do
show ip int brief =====> virtual group made
At this point we need to associate
a virtual template to bba-group which we define (TESTGROUP). A Virtual Template
is define so that any user who will come through the virtual interface (define
later) so all parameters which are set in this Virtual Template will be apply
on them. Blow is the definition of the virtual template which associate it to
the bba-group.
SP-Server (config-bba-group)#
virtual-template 1 =====>
only this to associate with group
Now I will create the virtual
interface and will associate to the virtual template that I define above.
SP-Server (config)# interface
virtual-template 1 ======>
same no as defined above
SP-Server (config-if)#
========> now we are in template
interface and what we define here will be for all those user who dial here in
on this interface.
SP-Server (config-if)# do show ip
int brief
Virtual-Access is the bba-group
Virtual-Template 1
SP-Server (config-if)# ip address
192.168.1.1 255.255.255.0
SP-Server (config)# default
interface fast1/0
SP-Server (config)# int fas1/0
SP-Server (config-if)# pppoe
enable group TESTGROUP
SP-Server#debug pppoe packet
CLIENT-SIDE CONFIGURATION
DSL-Client(config)# int fa0/0
DSL-Client (config-if)#
pppoe-clinet dial-pool-number 10
DSL-Client (config-if)# do show
ip int brief
Now we will create a Dialer
Interface which is sued to dial virtually out to SP-Server.
DSL-Client (config)# interface
dialer 1
NOTE: We can use DHCP or static
ip here, i will show both methods here, first static IP
DSL-Client(config-if)# ip address
192.168.1.10 255.255.255.0
DSL-Client(config-if)# encapsulation ppp
Now we will associate this
interface (Dialer) to the dial-pool (define above)
DSL-Client (config-if)# dialer
pool 10
DSL-Client # debug ppoe packets
We have dialer interface here on DSL-Client
and mean while see the debug on DSL-Client side which send the broadcast
messages, mac-address, this is basically the DSL-Client is dialling the
SP-Server.
*Jul 15 19:01:09.431: pppoe_send_padi:
FF FF FF FF FF FF CA 01 01 FC 00 1C 88 63 11 09
00 00 00 0C 01 01 00 00 01 03 00 04 64 56 34 5C ...
SP-Server(config-if)#
*Jul 15 19:01:57.927: PPPoE 0: I PADI R:ca01.01fc.001c L:ffff.ffff
FF FF FF FF FF FF CA 01 01 FC 00 1C 88 63 11 09
00 00 00 0C 01 01 00 00 01 03 00 04 64 56 34 5C ...
*Jul 15 19:01:57.931: PPPoE 0: O PADO, R:ca00.01fc.001c L:ca01.01fc
*Jul 15 19:01:57.931: Service tag: NULL Tag
CA 01 01 FC 00 1C CA 00 01 FC 00 1C 88 63 11 07
00 00 00 2D 01 01 00 00 01 03 00 04 64 56 34 5C ...
*Jul 15 19:01:58.435: %LINK-3-UPDOWN: Interface FastEthernet1/0, ch
o up
*Jul 15 19:01:58.435: %ENTITY_ALARM-6-INFO: CLEAR INFO Fa1/0 Physic
istrative State Down
*Jul 15 19:01:59.435: %LINEPROTO-5-UPDOWN: Line protocol on Interfa
et1/0, changed state to up
*Jul 15 19:02:00.015: PPPoE 0: I PADR R:ca01.01fc.001c L:ca00.01fc
CA 00 01 FC 00 1C CA 01 01 FC 00 1C 88 63 11 19
00 00 00 2D 01 01 00 00 01 03 00 04 64 56 34 5C ...
*Jul 15 19:02:00.047: [1]PPPoE 1: O PADS R:ca01.01fc.001c L:ca00.0
0
CA 01 01 FC 00 1C CA 00 01 FC 00 1C 88 63 11 65
00 01 00 2D 01 01 00 00 01 03 00 04 64 56 34 5C ...
*Jul 15 19:02:03.183: [1]PPPoE 1: Vi1.1 O FS
*Jul 15 19:01:57.927: PPPoE 0: I PADI R:ca01.01fc.001c L:ffff.ffff
FF FF FF FF FF FF CA 01 01 FC 00 1C 88 63 11 09
00 00 00 0C 01 01 00 00 01 03 00 04 64 56 34 5C ...
*Jul 15 19:01:57.931: PPPoE 0: O PADO, R:ca00.01fc.001c L:ca01.01fc
*Jul 15 19:01:57.931: Service tag: NULL Tag
CA 01 01 FC 00 1C CA 00 01 FC 00 1C 88 63 11 07
00 00 00 2D 01 01 00 00 01 03 00 04 64 56 34 5C ...
*Jul 15 19:01:58.435: %LINK-3-UPDOWN: Interface FastEthernet1/0, ch
o up
*Jul 15 19:01:58.435: %ENTITY_ALARM-6-INFO: CLEAR INFO Fa1/0 Physic
istrative State Down
*Jul 15 19:01:59.435: %LINEPROTO-5-UPDOWN: Line protocol on Interfa
et1/0, changed state to up
*Jul 15 19:02:00.015: PPPoE 0: I PADR R:ca01.01fc.001c L:ca00.01fc
CA 00 01 FC 00 1C CA 01 01 FC 00 1C 88 63 11 19
00 00 00 2D 01 01 00 00 01 03 00 04 64 56 34 5C ...
*Jul 15 19:02:00.047: [1]PPPoE 1: O PADS R:ca01.01fc.001c L:ca00.0
0
CA 01 01 FC 00 1C CA 00 01 FC 00 1C 88 63 11 65
00 01 00 2D 01 01 00 00 01 03 00 04 64 56 34 5C ...
*Jul 15 19:02:03.183: [1]PPPoE 1: Vi1.1 O FS
*Jul 15 19:01:57.879: pppoe_send_padi:
FF FF FF FF FF FF CA 01 01 FC 00 1C 88 63 11 09
00 00 00 0C 01 01 00 00 01 03 00 04 64 56 34 5C ...
*Jul 15 19:01:57.979: PPPoE 0: I PADO R:ca00.01fc.001c L:ca01.01fc.001c Fa1/0
CA 01 01 FC 00 1C CA 00 01 FC 00 1C 88 63 11 07
00 00 00 2D 01 01 00 00 01 03 00 04 64 56 34 5C ...
*Jul 15 19:01:59.943: OUT PADR from PPPoE Session
CA 00 01 FC 00 1C CA 01 01 FC 00 1C 88 63 11 19
00 00 00 2D 01 01 00 00 01 03 00 04 64 56 34 5C ...
*Jul 15 19:02:00.139: PPPoE 1: I PADS R:ca00.01fc.001c L:ca01.01fc.001c Fa1/0
CA 01 01 FC 00 1C CA 00 01 FC 00 1C 88 63 11 65
00 01 00 2D 01 01 00 00 01 03 00 04 64 56 34 5C ...
*Jul 15 19:02:00.167: %DIALER-6-BIND: Interface Vi1 bound to profile Di1
*Jul 15 19:02:00.267: %LINK-3-UPDOWN: Interface Virtual-Access1, changed state t
o up
*Jul 15 19:02:03.151: %LINEPROTO-5-UPDOWN: Line protocol on Interface Virtual-Ac
cess1, changed state to up
*Jul 15 19:02:03.307: [0]PPPoE 1: Vi1 O FS
*Jul 15 19:02:13.555: [0]PPPoE 1: Vi1 O FS
*Jul 15 19:02:23.827: [0]PPPoE 1: Vi1 O FS
We can also see the PPPoe session made between SP-Server and DSL-Client.
SP-Server#show pppoe session*Jul 15 19:08:52.779: [1]PPPoE 1: Vi1.1 O FS
1 session in LOCALLY_TERMINATED (PTA) State
1 session total
Uniq ID PPPoE RemMAC Port VT VA State
SID LocMAC VA-st
1 1 ca01.01fc.001c Fa1/0 1 Vi1.1 PTA
ca00.01fc.001c UP
Using DHCP
I hope you all know about how to
configure DHCP on Routers, if not Please see Cisco Router as DHCP Server.
Please remove manual IP address
from interface fas1/0 and dialer on DSL-Client and make the method as DHCP and
configure DHCP on SP-Server. The configuration is given below:
SP-Server:
ip dhcp excluded-address
192.168.1.1 192.168.1.10
ip dhcp pool POOLFORPPPOE
network 192.168.1.0 255.255.255.0
interface Virtual-Template1
ip address 192.168.1.1 255.255.255.0
peer default ip address dhcp-pool POOLFORPPPOE
DSL-Client
DSL-Client(config)#interface
fa1/0
DSL-Client(config-if)#no ip
address
DSL-Client(config-if)#ip address
dhcp =====> Add this command
DSL-Client(config)#interface
dialer 1
DSL-Client(config-if)#no ip
address
DSL-Client(config-if)#ip address
dhcp
Interface IP-Address OK? Method Status Prot
ocol
FastEthernet0/0 unassigned YES unset administratively down down
DSL-Client#show pppoe session
1 client session
SID LocMAC VA-st
N/A 2 ca00.01fc.001c Fa1/0 Di1 Vi1 UP
ca01.01fc.001c UP
