[j-nsp] M10i Version 7.0 R1.5 Per-packet Load Balancing

[Harry Reynolds]

Note that per-packet is really per flow, and that a hack algorithm is
used to select the next hop. I suspect that the presence of option when
performing a source-route is affecting the hash, and therefore altering
the next hop. Put another way, it is not uncommon to see per flow
balancing not select all possible next-hops when there are only a few
flows because not every bit in the IP and transport headers is hashed
against.


HTHs

 

> -----Original Message-----
> From: juniper-nsp-bounces at puck.nether.net 
> [mailto:juniper-nsp-bounces at puck.nether.net] On Behalf Of 
> Thomas, Steven
> Sent: Monday, June 13, 2005 1:22 PM
> To: juniper-nsp at puck.nether.net
> Subject: [j-nsp] M10i Version 7.0 R1.5 Per-packet Load Balancing 
> 
> I have been through the documentation and the archives of 
> this mailing list and I'm at wit's end.  I believe I've set 
> this up so it should work but it doesn't seem to EXCEPT when 
> I ping with the route-record option on.  Then it works 
> perfectly.  Other traffic, such as plain pings, ftp and 
> telnet always take the same route.  
> 
> This is the Junos config:
> 
> interfaces {
>     fe-0/0/0 {
>         unit 0 {
>             family inet {
>                 address 10.10.152.253/24;
>             }
>         }
>     }
>     fe-0/0/1 {
>         unit 0 {
>             family inet {
>                 address 10.10.153.253/24;
>             }
>         }
>     }
>     at-0/2/0 {
>         mtu 9192;
>         clocking internal;
>         atm-options {
>             vpi 15;
>         }
>          unit 15102 {
>             point-to-point;
>             vci 15.102;   
>             family inet {
>                 address 172.16.1.5/30;
>             }
>         }
>     }
> routing-options {
>     static {
>         route 192.168.168.0/24 {
>             next-hop [ 10.10.153.1 172.16.1.6 ];
>             metric 1;
>             preference 150;
>         }
>     }
>     forwarding-table {
>         export load-balance;
>     }
> }
> policy-options {
>     policy-statement load-balance {
>         from {
>             route-filter 192.168.168.0/24 exact;
>         }
>         then {
>             load-balance per-packet;
>         }
>     }
> }
> 
> FE-0/0/0,10.10.152.0/24 is connected to a Linux box which is 
> my traffic source.  Fe-0/0/1,10.10.153.0/24 connects to 
> virtual router A on an ERX and at-0/2/0.15102 connects to 
> virtual router B on the same ERX.
> 192.168.168.0/24 is an ethernet containing two Sun boxes 
> which are my traffic destinations and resides on virtual 
> router B. Virtual router A and B are directly connected with 
> another ethernet.
> 
> This is the output of show route 192.168.168.0/24 extensive:
> 
> 192.168.168.0/24 (1 entry, 1 announced)
> TSI:
> KRT in-kernel 192.168.168.0/24 -> {10.10.153.1, 172.16.1.6}
>         *Static Preference: 150
>                 Next-hop reference count: 2
>                 Next hop: 10.10.153.1 via fe-0/0/1.0
>                 Next hop: 172.16.1.6 via at-0/2/0.15102, selected
>                 State: <Active Int Ext>
>                 Age: 4:33:55    Metric: 1       Tag: 0
>                 Task: RT
>                 Announcement bits (1): 0-KRT
>                 AS path: I
> 
> {master}
> 
> Is there something wrong with my config or is there a bug in 
> this version or what?  Any help would be appreciated.
> 
> Steve Thomas
> 
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