The subject is very broad and not easily explained. The short
answer to you direct question is that packets can be classified as
they enter a router into a forwarding class by various methods.
This marks the packet to be placed into a Queue on the outgoing
interface. When the packet leaves the router the DSCP (or EXP etc)
bits are re-written depending on the re-write rules. There are a
set of default re-write rules already activated which you can see
using the command:
'show class-of-service rewrite-rule'
This is the general mechanism but the subject is very broad and not
easily explained in one e-mail.
Let me give you some pointers and some links to other documentation.
Some examples:
If you wish to change the DSCP bits of packets that enter the router
with more granularity then you need to apply a filter or classifier
on the input interface.
You can match on most of the IPv4 and IPv6 header and mark the DSCP
bits accordingly.
Here is a simple filter example:
filter test {
term a {
from {
protocol ipv4;
}
then {
forwarding-class assured-forwarding;
accept;
}
}
term b {
from {
protocol ipv6;
}
then {
forwarding-class best-effort;
accept;
}
}
}
Here is an example of classifying a whole logical unit to a
forwarding class:
set class-of-service interfaces ge-0/0/0 unit 1 forwarding-class
expedited-forwarding
Interface configuration:
http://www.juniper.net/techpubs/software/junos/junos62/swconfig62-interfaces/html/ CoS overview:
http://www.juniper.net/techpubs/software/junos/junos62/swconfig62-interfaces/html/interfaces-cos-overview.html#1015298 CoS configuration:
http://www.juniper.net/techpubs/software/junos/junos62/swconfig62-interfaces/html/statement-hierarchy-interfaces.html#1013885 Here is a link on configuring firewalls:
http://www.juniper.net/techpubs/software/junos/junos62/swconfig62-policy/download/firewall-config.pdf I hope this helps
Gary
Dragan Mickovic wrote:
> Not much expirience with this topic, but I think the following will give you
> some idea:
>
> http://www.juniper.net/techpubs/software/junos/junos62/swconfig62-interfaces/html/statement-hierarchy-interfaces2.html#1013915
>
> micko
>
> On Thu, Feb 12, 2004 at 03:53:47PM -0300, Giuliano Cardozo Medalha wrote:
>
>>Hi,
>>
>>We need help about juniper M20 routers.
>>
>>With a router with a Gigabit Ethernet IQ interface and POS STM-1 for WAN
>>conection,
>>how is possible to mark packets IPv4 and IPv6 with DSCP field ?
>>
>>What command should be used to mark IP packets on M20 router .... junos
>>6.2 ?
>>
>>Thanks a lot
>>
>>Giuliano
>
> _______________________________________________
> juniper-nsp mailing list juniper-nsp@puck.nether.net
> http://puck.nether.net/mailman/listinfo/juniper-nsp
>