Why does PPPoE link has low bandwidth utilization compared to static INET connection?

MVP
MVP
Problem:

A typical Aruba SDWAN Branch Gateway will have one or more uplinks. 

There are times when the uplink being used has combination of Static, DHCP or PPPoE.

Despite configuring all the uplink with same weight say "10", we will see some link taking higher load than the other.



Diagnostics:

This problem will occur not due to the weight in Load Balancing but with route weight.

For example: 

In the below output we see the load balancing not happening properly. VLAN 4094 has utilized the least bandwidth despite having same weight "10"

#show uplink debug 

Uplink Manager: Enabled
Uplink Health-check: Enabled  FQDN: pqm.arubanetworks.com(13.234.96.243)
Uplink Load-balancing:Enabled  Mode: Round-robin  

Uplink Management Table
-----------------------
Uplink Type  Properties  Uplink-id      State      Gateway        Reachability  WAN Type   Speed       Weight  B/w utiln  Max b/w
-----------  ----------  ---------      -----      -------        ------------  --------   -----       ------  ---------  -------
Wired        vlan 3000   PPPoE          Connected  46.93.112.1    Reachable      Internet  1.000 Gbps     10   0.01%        100%
Wired        vlan 3001   Static1        Connected  192.168.1.1    Reachable      Internet  1.000 Gbps     10   2.32%        100%
Wired        vlan 3002   Static2        Connected  192.168.2.1    Reachable      Internet  1.000 Gbps     10   2.19%        100%

#show datapath uplink verbose

Datapath Uplink Table Entries
-----------------------------
Vlan  Srvc-type  Link-id  Reachable  Weight (rweight)  Bw-utiln  Sessions      WAN Excep Sessions  WAN hits  HA peer tnl  Rwgt-curr  Max-bw  Bw-cap
----  ---------  -------  ---------  ----------------  --------  --------      ------------------  --------  -----------  ---------  ------  ------
3000  Internet    101     YES          10 ( 333)        0.01%    2411 ( 6%)    0                   0         0               0       100%    1000 Mbps
3001  Internet    102     YES          10 ( 333)        2.32%    16967 ( 46%)  0                   0         0               0       100%    1000 Mbps
3002  Internet    103     YES          10 ( 333)        2.19%    17015 ( 46%)  0                   0         0               0       100%    1000 Mbps

Please note the static route for PPPoE is not listing below

show ip route 

Codes: C - Connected, O - OSPF, IA - OSPF Inter Area, E1 - OSPF External Type 1
       E2 - OSPF External Type 2, B I - BGP Interior, B E - BGP Exterior, S - Static
       U - BGW Peer Uplink, M - Management, Ru - Route Usable, * - Candidate Default
       V - RAPNG VPN/Branch, I - Crypto-Cfgset, N - Not Redistributed, Bc - Cloud Overlay Protocol

S*    0.0.0.0/0  [50/1] via 192.168.1.1
                 [50/1] via 192.168.2.1


Solution

The problem here is that the default Route cost of Static default gateway is 1 where as the Static route cost of PPPoE/DHCP link is 10.

The solution to this problem would be to change the cost of the static default gateway of VLAN 3001 and 3002 from 1 to 10 from Aruba Central.
After the change is done, it is commended to shut the PPPoE link once and unshut it so that the link can participate in load balancing

In the below output we see the load balancing working fine with different uplinks

#show uplink debug 

Uplink Manager: Enabled
Uplink Health-check: Enabled  FQDN: pqm.arubanetworks.com(13.234.96.243)
Uplink Load-balancing:Enabled  Mode: Round-robin  

Uplink Management Table
-----------------------
Uplink Type  Properties  Uplink-id      State      Gateway        Reachability  WAN Type   Speed       Weight  B/w utiln  Max b/w
-----------  ----------  ---------      -----      -------        ------------  --------   -----       ------  ---------  -------
Wired        vlan 3000   PPPoE          Connected  46.93.112.1    Reachable      Internet  1.000 Gbps     10   1.04%        100%
Wired        vlan 3001   Static1        Connected  192.168.1.1    Reachable      Internet  1.000 Gbps     10   1.19%        100%
Wired        vlan 3002   Static2        Connected  192.168.2.1    Reachable      Internet  1.000 Gbps     10   1.13%        100%

#show datapath uplink verbose

Datapath Uplink Table Entries
-----------------------------
Vlan  Srvc-type  Link-id  Reachable  Weight (rweight)  Bw-utiln  Sessions      WAN Excep Sessions  WAN hits  HA peer tnl  Rwgt-curr  Max-bw  Bw-cap
----  ---------  -------  ---------  ----------------  --------  --------      ------------------  --------  -----------  ---------  ------  ------
3000  Internet    101     YES          10 ( 333)        0.01%    10792 ( 33%)    0                   0         0               0       100%    1000 Mbps
3001  Internet    102     YES          10 ( 333)        2.32%    10570 ( 32%)    0                   0         0               0       100%    1000 Mbps
3002  Internet    103     YES          10 ( 333)        2.19%    10768 ( 33%)    0                   0         0               0       100%    1000 Mbps


You can verify the routing table with the updated route of the PPPoE link as well as highlighted below

 

show ip route 

Codes: C - Connected, O - OSPF, IA - OSPF Inter Area, E1 - OSPF External Type 1
       E2 - OSPF External Type 2, B I - BGP Interior, B E - BGP Exterior, S - Static
       U - BGW Peer Uplink, M - Management, Ru - Route Usable, * - Candidate Default
       V - RAPNG VPN/Branch, I - Crypto-Cfgset, N - Not Redistributed, Bc - Cloud Overlay Protocol

S*    0.0.0.0/0  [50/1] via 83.24.145.1
                 [50/1] via 192.168.248.1 
                 [50/1] via 192.168.249.1
Version history
Revision #:
1 of 1
Last update:
4 weeks ago
Updated by:
 
Search Airheads
cancel
Showing results for 
Search instead for 
Did you mean: