* SV: [daniel@netatonce.se: SV: [LARTC] TEQL: 2 Mbit eth1 + 2Mbit eth2 = 1Mbit teql0]
2000-10-10 14:21 SV: [daniel@netatonce.se: SV: [LARTC] TEQL: 2 Mbit eth1 + 2Mbit eth2 = 1Mbit teql0] Daniel
@ 2000-10-10 16:03 ` bert
2000-10-11 10:36 ` bert
1 sibling, 0 replies; 3+ messages in thread
From: bert @ 2000-10-10 16:03 UTC (permalink / raw)
To: lartc
<PRE>On Tue, Oct 10, 2000 at 04:21:06PM +0200, Daniel Bergqvist wrote:
><i> The logs are at <A HREF="http://www.bergqvist.se/teql/.">http://www.bergqvist.se/teql/.</A>
</I>><i>
</I>><i> The speed is about 1.3Mbit/s.
</I>
There is lots of packetloss. Also, it is obvious from this dump that
lan_router is sending both over eth1 and eth2, but that the wan router is
only receiving on eth2, and not on eth1, or that your dump failed.
lan_router_eth1 10-Oct-2000 16:16 73k
lan_router_eth2 10-Oct-2000 16:16 73k
lan_router_teql0 10-Oct-2000 16:16 42k
wan_router_eth1 10-Oct-2000 16:15 1k
wan_router_eth2 10-Oct-2000 16:15 46k
wan_router_teql0 10-Oct-2000 16:15 146k
lan_router_eth[12] carry ftp data, teql0 carries acknowledgements, and lots
of them are duplicate or triplicate, indicating packetloss and resends.
wan_router_eth1 receives almost nothing, while wan_router_eth2 is sees the
same the ACKs seen by teql0 on the lan_router, also duplicate.
wan_router_teql0 sees packets also seen by lan_router_eth1 and eth2, and
they are alternatingly from eth1 and eth2, which is as it should be.
10.2.18.2 is telling ftp2.citynet.nu that is is missing packets, so it
appears that data is getting lost on the other way. I'm not sure if this is
related to TEQL.
I'm interested in knowing what you make of the nearly empty wan_router_eth1
file.
Regards,
bert hubert
--
PowerDNS Versatile DNS Services
Trilab The Technology People
'SYN! .. SYN|ACK! .. ACK!' - the mating call of the internet
</PRE>
^ permalink raw reply [flat|nested] 3+ messages in thread* SV: [daniel@netatonce.se: SV: [LARTC] TEQL: 2 Mbit eth1 + 2Mbit eth2 = 1Mbit teql0]
2000-10-10 14:21 SV: [daniel@netatonce.se: SV: [LARTC] TEQL: 2 Mbit eth1 + 2Mbit eth2 = 1Mbit teql0] Daniel
2000-10-10 16:03 ` bert
@ 2000-10-11 10:36 ` bert
1 sibling, 0 replies; 3+ messages in thread
From: bert @ 2000-10-11 10:36 UTC (permalink / raw)
To: lartc
<PRE>On Tue, Oct 10, 2000 at 06:03:44PM +0200, bert hubert wrote:
><i> On Tue, Oct 10, 2000 at 04:21:06PM +0200, Daniel Bergqvist wrote:
</I>><i> > The logs are at <A HREF="http://www.bergqvist.se/teql/.">http://www.bergqvist.se/teql/.</A>
</I>><i> >
</I>><i> > The speed is about 1.3Mbit/s.
</I>><i>
</I>><i> There is lots of packetloss. Also, it is obvious from this dump that
</I>><i> lan_router is sending both over eth1 and eth2, but that the wan router is
</I>><i> only receiving on eth2, and not on eth1, or that your dump failed.
</I>
On second thought, there is no packet loss. This is expected behaviour, it
appears, see <A HREF="http://www.kernelnotes.de/kt/latest.html:">http://www.kernelnotes.de/kt/latest.html:</A>
Alexey Kuznetsov was critical of this explanation, and said that multipath
routing worked "perfectly when you need to split load on servers talking to
enough large number of clients. Any
http server is good example." He added that Andi's suggestion of the
existing eql, teql and bonding devices, would introcude "even worse problem
of strong tcp reordering. Actually,
experiments show that load balancing works only in the situations, when
congestion window is bounded by 3 packets. If it is not made artificially,
it occurs automatically on each connection
after some amount of excessive retransmissions. Total single TCP
connection throughput is never better in this case. Actually, it hints to
the thought that "true load blalancing" has to
involve tracking connections and avoiding reordering TCP packets."
There was no reply to this, but there was a bit of implementation discussion
elsewhere, along the lines of Andi's
explanations.
----
You might consider using google a bit to find out about packet reordering -
packets arrive out of sequence on eth1 and eth2, which the kernel interprets
as packetloss.
Regards,
bert hubert
--
PowerDNS Versatile DNS Services
Trilab The Technology People
'SYN! .. SYN|ACK! .. ACK!' - the mating call of the internet
</PRE>
^ permalink raw reply [flat|nested] 3+ messages in thread