Note of the configuration in AR G3 as a PPPoE client

Publication Date:  2014-09-15 Views:  951 Downloads:  0
Issue Description
When AR G3 series work as PPPoE clients,there are some common configuration error lead to failed dialer, fail in accessing internet and low speed surfing. 
Alarm Information
N/A
Handling Process
To configure PPPoE-client dial dual uplink(the primary and backup links) by setting different priority route.
#
interface Dialer0
link-protocol ppp
ppp chap user 123456
ppp chap password simple 123456
ppp pap local-user 123456 password  simple 123456
tcp adjust-mss 1200
ip address ppp-negotiate
dialer user server
dialer bundle 1
dialer timer idle 3600
dialer-group 1
nat outbound 2000
#
interface Dialer1
link-protocol ppp
ppp chap user 123456
ppp chap password simple 123456
ppp pap local-user 123456 password  simple 123456
tcp adjust-mss 1200
ip address ppp-negotiate
dialer user server
dialer bundle 2
dialer timer idle 3600
dialer-group 2
nat outbound 2000
#
interface GigabitEthernet0/0/2
pppoe-client dial-bundle-number 1 on-demand
pppoe-client dial-bundle-number 2 on-demand

#
interface NULL0
#
dialer-rule
dialer-rule 1 ip permit
dialer-rule 2 ip permit
#
ip route-static 0.0.0.0 0.0.0.0 Dialer0
ip route-static 0.0.0.0 0.0.0.0 Dialer1 preference 100
Root Cause
The configuration point 1 of Dialer interface: as to the PPP authentication, chap or pap? To ensure successful authentication , we can configured both of them on the local client.

The configuration point 2 of Dialer interface: is there a need to perform that the local device authenticates the remote device. If Yes, we should configure ppp authentication-mode { chap | pap } to enable authentication and set the mode. If No, we can’t configure this comman, because that PPP authentication is not performed by default and may lead to failed authentication and link would not go up.

The configuration point 3 of Dialer interface: tcp adjust-mss value  this command is going to modify the size of the MSS (Max Segment Size) which was the negotiated in TCP negotiation stage, to make sure that the length of the message is less than the dial-up port MTU value, and the recommended value is 1200, you can ensure that the message can be processed normally , and solve the problem of low speed surfing.

The configuration point 4 of Dialer interface: ip address ppp-negotiate  this command configures IP address negotiation to allow the dailer interface to obtain an IP address from the remote device.

The configuration point 5 of Dialer interface: dialer user user-name this command is enable the DCC function, and we can define this user-name by ourselves.

The configuration point 6 of Dialer interface: dialer bundle number this command is going to associate the physical interface with dial-up interface, so this number should be consistent with pppoe-client dial-bundle-number numbe of the physical port.

The configuration point 7 of Dialer interface: dialer-group number this command specifies the group number of dial-up access which the interface belongs to, and determined by the number dialer-rule.

The configuration point 8 of Dialer interface: nat outbound number  if there is a need to NAT , we can configure the nat outbound under the dialer interface.
Suggestions
when configuring PPPoE-client dial dual uplink, it is not recommended to use common equal-cost routes to realize load balancing, because if the dual uplink access into  two carriers, which  the back packet delays of  the two networkare are inconsistent, which can lead to random sequence, retransmission, and low speed surfing.

END