[LARTC] TEQL question

[Rene 'Lynx' Pfeiffer linux@thing.at]

<PRE>Hello, LARTC!

I have a question concerning TEQL. I have set up two Linux routers for
experimental purposes (kernel 2.4.0-test9). Every router controls 8 modems, one
of the machines is configured as a PPP dial-in server (ppp 2.4b4).

The idea is to increase throughput between both machines via TEQL queuing. This
works quite well, but unfortunately TEQL distributes the network load not as
equal as the name TEQL might suggest. If I use ICMP floods all 8 links are
uniformly under load. The same is true for UDP floods. When using single TCP
transfers (for example SCP from the SSH package) not all 8 links are used. The
packets use 3 or 4 links of the 8.

The questions is why. I have done some experiments with various applications
(FTP, NFS, SMTP, Real Audio/Video, Netmeeting, ELSA Vision). So far TEQL uses
only all 8 links when I flood the routers with packets.

Any ideas? I would like to distribute the load over all 8 links.

Here are the configs (brief, note that some options are heavily influenced by
my experiments and not meant to be used in &quot;production&quot; environments):

PPP options dial-in router:
----------------------------

# PPPD options
SERVER_PPP=&quot;192.168.20.1 192.168.20.2 192.168.20.3 192.168.20.4
            192.168.20.5 192.168.20.6 192.168.20.7 192.168.20.8&quot;
SERVER_NET=&quot;192.168.20.0/24&quot;
CLIENT_PPP=&quot;192.168.00&quot;
CLIENT_NET=&quot;192.168.0.0/24&quot;
CLIENT=&quot;192.168.10.230&quot;

MTU=&quot;1500&quot;

SERVER_OPT=&quot;lock asyncmap 0 maxfail 0 idle 300 proxyarp
            logfile /var/log/ppp noauth debug kdebug 3 noipdefault
            persist crtscts&quot;
MULTILINK=&quot;multilink&quot;
IPCP_OPTS=&quot;lcp-max-configure 30 lcp-max-failure 30 ipcp-max-terminate 10
           ipcp-max-configure 20 ipcp-max-failure 20&quot;
COMP_OPTS=&quot;novj novjccomp nobsdcomp nodeflate&quot;

SPEEDW600

After all 8 PPP daemons are initialized I set the routing:

# Activate teql0 and set routing

echo 0 &gt; /proc/sys/net/ipv4/conf/all/rp_filter

$TCC qdisc add dev lo root teql0
$IPC link set teql0 mtu $MTU up
$TCC qdisc del dev lo root teql0
$IPC route add $CLIENT_NET dev teql0
$IPC route add $CLIENT dev teql0

$IPC and $TCC is the path to the ip and the tc binary. The pppX devices are
automatically added to the TEQL queue via the PPP daemon scripts
/etc/ppp/if-up.local and /etc/ppp/if-down.local.

/etc/ppp/if-up.local (basically):

# Put link to teql0 heap
[ ${DEBUG} = &quot;yes&quot; ] &amp;&amp; logger &quot;Adding $1 to teql0 queue&quot;
$TC qdisc add dev $1 root teql0

[ ${DEBUG} = &quot;yes&quot; ] &amp;&amp; logger &quot;Adding local address $4 to teql0&quot;
$IP addr  add $4 dev teql0

[ ${DEBUG} = &quot;yes&quot; ] &amp;&amp; logger &quot;Deleting route to remote address $5&quot;
$IP route del $5

/etc/ppp/if-down.local:

# Remove link from teql0 heap
[ ${DEBUG} = &quot;yes&quot; ] &amp;&amp; logger &quot;Removing $1 from teql0 queue&quot;
$TC qdisc del dev $1 root teql0

PPP client machine:
--------------------

# PPPD options

SERVER_PPP=&quot;192.168.0.1 192.168.0.2 192.168.0.3 192.168.0.4
            192.168.0.5 192.168.0.6 192.168.0.7 192.168.0.8&quot;
SERVER_NET=&quot;192.168.0.0/24&quot;
SERVER=&quot;192.168.10.231&quot;
CLIENT_PPP=&quot;192.168.20&quot;
CLIENT_NET=&quot;192.168.20.0/24&quot;

MTU=&quot;1500&quot;

#CLIENT_OPT=&quot;-detach lock crtscts persist demand idle 1200
             noipdefault init /etc/ppp/chat/init.sh debug kdebug 2
             holdoff 5 noauth novj nobsdcomp nodeflate multilink
             logfile /var/log/ppp&quot;

CLIENT_OPT=&quot;nolock asyncmap 0 maxfail 0 holdoff 2 demand persist
            crtscts passive noipdefault proxyarp logfile /var/log/ppp
            noauth debug kdebug 3&quot;
PCP_OPT=&quot;lcp-max-configure 20 lcp-max-failure 20&quot;
COMPT_OPT=&quot;&quot;

SPEED\x19200

# Get all active PPP links
cd /proc/sys/net/ipv4/conf/
PPPDEVS=`ls -1d ppp*`

# Disable RP filter
echo 0 &gt; /proc/sys/net/ipv4/conf/all/rp_filter

# Equalize links
for LINK in $PPPDEVS
do
    echo &quot;Adding $LINK...&quot;
    $TCC qdisc add dev $LINK root teql0
    $IPC addr  add `/usr/local/bin/getpppinfo -l $LINK` dev teql0
    $IPC route del `/usr/local/bin/getpppinfo -r $LINK`
done

# Activate teql0 and set routing
$IPC link set teql0 mtu $MTU up
$IPC route add $SERVER_NET dev teql0
$IPC route add $SERVER dev teql0


Sorry for the script mess. I was glad to see it work and did not have much time
for code clean-ups.

Best regards,
René

 GNU/Linux Manages! - Support, Administration, Consulting
  RP3191-RIPE       - Networking, Programming, Installation




</PRE>