3 Jan
2013
3 Jan
'13
3 p.m.
On Thursday, January 03, 2013 22:16:32 Jan Lühr wrote:
We noticed a few, unusual things:
-> regardless of the link tested (kif or fastd3) and regardless of the node
(node1, node2) small interruptions (loss-peaks) are appearing. -> These
peaks appear almost synchronous, a few "noise" comes from different
vpn-links and node-wan-uplinks. -> Since all links are wired, radio-noise
won't have an impact
-> The losses appear in batman-adv 2011.2.0 as well as in batman-adv
2012.4.0. Thus I suspect that batman-adv is triggering theses
interruptions.
If you believe batman-adv is the culprit, please remove batman-adv from your
test setup and repeat the exact same test. Otherwise we move into the realm of
speculation.
Haven't heard of any "peak loss" due to batman-adv.
Cheers,
Marek
PS: Forgot to click "reply to all", sorry for that.
3 Jan
3 Jan
3:52 p.m.
New subject: [B.A.T.M.A.N.] Packet-Loss-Peaks in a Freifunk-Network
Hello,
Am 03.01.2013 um 16:00 schrieb Marek Lindner:
On Thursday, January 03, 2013 22:16:32 Jan Lühr
wrote:
Well, I started echoing on the underlying VPN-connection as well and changed the
chart-titles for clearance:
In chart 4 and chart 5 RTT / Loss from kif.kbu to node-1 is measured.
In chart 4 kif is sending ICMPv6 to the link-local address of bat0-interface - in chart 5
the link_local address of the underlying vpn-interface is used.
The loss-peaks appear in char 4 (bat0) only.
Thanks for your help,
Keep smiling
yanosz
We noticed a few, unusual things:
-> regardless of the link tested (kif or fastd3) and regardless of the node
(node1, node2) small interruptions (loss-peaks) are appearing. -> These
peaks appear almost synchronous, a few "noise" comes from different
vpn-links and node-wan-uplinks. -> Since all links are wired, radio-noise
won't have an impact
-> The losses appear in batman-adv 2011.2.0 as well as in batman-adv
2012.4.0. Thus I suspect that batman-adv is triggering theses
interruptions.
If you believe batman-adv is the culprit, please remove batman-adv from your
test setup and repeat the exact same test. Otherwise we move into the realm of
speculation.
PS: Forgot to click "reply to all", sorry for that.
Well, I set it f2up this list, since you're node subscribed. Sorry for not mentioning
it.
4:05 p.m.
New subject: [B.A.T.M.A.N.] Packet-Loss-Peaks in a Freifunk-Network
On Thursday, January 03, 2013 23:52:42 Jan Lühr wrote:
Well, I started echoing on the underlying
VPN-connection as well and
changed the chart-titles for clearance:
In chart 4 and chart 5 RTT / Loss from kif.kbu to node-1 is measured.
In chart 4 kif is sending ICMPv6 to the link-local address of
bat0-interface - in chart 5 the link_local address of the underlying
vpn-interface is used.
All tests are from the same node to the same node using exactly the same means
(protocols, etc) with the exception of batman-adv ? Sorry for my dumb question
but your topology might be obvious to you but isn't for me (us?).
The spikes on your graphs show the packet loss ? How can we have a RTT < 50ms
while experiencing packet loss ?
Cheers,
Marek
4:17 p.m.
New subject: [B.A.T.M.A.N.] Packet-Loss-Peaks in a Freifunk-Network
Hello,
Am 03.01.2013 um 17:05 schrieb Marek Lindner:
On Thursday, January 03, 2013 23:52:42 Jan Lühr
wrote:
yes.
Well, I started echoing on the underlying
VPN-connection as well and
changed the chart-titles for clearance:
In chart 4 and chart 5 RTT / Loss from kif.kbu to node-1 is measured.
In chart 4 kif is sending ICMPv6 to the link-local address of
bat0-interface - in chart 5 the link_local address of the underlying
vpn-interface is used.
All tests are from the same node to the same node using exactly the same means
(protocols, etc) with the exception of batman-adv ? Sorry for my dumb question
but your topology might be obvious to you but isn't for me (us?).
The spikes on your graphs show the packet loss ?
yes.
How can we have a RTT < 50ms
while experiencing packet loss ?
Collectd uses a ping rate of 10 seconds here, RTT >= 0.9s = 900ms is "loss"
If 1/3 arrives in < 50ms and 2/3 are lost, RTT is < 50ms while loss = 2/3.
Btw. I you wanna see our setup, we can take a tour via ssh / tmux - I can provide the
rrd-Files, too.
You can contact my by jabber (yanosz(a)jabber.ccc.de) as well,
Thanks,
Keep smiling
yanosz
4 Jan
4 Jan
5:34 a.m.
New subject: [B.A.T.M.A.N.] Packet-Loss-Peaks in a Freifunk-Network
What were the exact batman-adv versions at the time you made those graphs for the shown
nodes as well as any intermediate nodes (although if I got your setup right then the nodes
in those graphs do not have any intermediate batman-adv hops involved, do they?)?
Does it make a difference if you make the entries in the neighbor solicitation table
permanent (e.g. with 'ip -6 neigh')?
Do the same spikes appear with a 'batctl ping' (or if adding such graphs is quite
a hassle then at least, is the overall 'batctl ping' packet loss similar to the
one from the ip ping)?
Do you see any "Changing route towards" events in the batman-adv logs between
these supposedly always direct neighbors - if yes, maybe with a similar frequency? Or even
better, check whether the same packet loss appears when isolating any of such pairs of
nodes so that no batman-adv route changes could happen at all.
Do these packet loss events correlate with periods of high OGM loss (e.g. check for high
last-seen values in the originator table)?
Gesendet: Donnerstag, 03. Januar 2013 um 17:17 Uhr
Von: "Jan Lühr" <ff(a)stephan.homeunix.net>
An: "The list for a Better Approach To Mobile Ad-hoc Networking"
<b.a.t.m.a.n(a)lists.open-mesh.org>
Betreff: Re: [B.A.T.M.A.N.] Packet-Loss-Peaks in a Freifunk-Network
Hello,
Am 03.01.2013 um 17:05 schrieb Marek Lindner:
On Thursday, January 03, 2013 23:52:42 Jan Lühr
wrote:
yes.
Well, I started echoing on the underlying
VPN-connection as well and
changed the chart-titles for clearance:
In chart 4 and chart 5 RTT / Loss from kif.kbu to node-1 is measured.
In chart 4 kif is sending ICMPv6 to the link-local address of
bat0-interface - in chart 5 the link_local address of the underlying
vpn-interface is used.
All tests are from the same node to the same node using exactly the same means
(protocols, etc) with the exception of batman-adv ? Sorry for my dumb question
but your topology might be obvious to you but isn't for me (us?).
The spikes on your graphs show the packet loss ?
yes.
How can we have a RTT < 50ms
while experiencing packet loss ?
Collectd uses a ping rate of 10 seconds here, RTT >= 0.9s = 900ms is "loss"
If 1/3 arrives in < 50ms and 2/3 are lost, RTT is < 50ms while loss = 2/3.
Btw. I you wanna see our setup, we can take a tour via ssh / tmux - I can provide the
rrd-Files, too.
You can contact my by jabber (yanosz(a)jabber.ccc.de) as well,
Thanks,
Keep smiling
yanosz
10:18 a.m.
New subject: [B.A.T.M.A.N.] Packet-Loss-Peaks in a Freifunk-Network
Hi Linus,
nice to hear from you again.
Am 04.01.2013 um 06:34 schrieb Linus Lüssing:
What were the exact batman-adv versions at the time
you made those graphs for the shown nodes as well as any intermediate nodes (although if I
got your setup right then the nodes in those graphs do not have any intermediate
batman-adv hops involved, do they?)?
Does it make a difference if you make the entries in the neighbor solicitation table
permanent (e.g. with 'ip -6 neigh')?
Do the same spikes appear with a 'batctl ping' (or if adding such graphs is quite
a hassle then at least, is the overall 'batctl ping' packet loss similar to the
one from the ip ping)?
Do you see any "Changing route towards" events in the batman-adv logs between
these supposedly always direct neighbors - if yes, maybe with a similar frequency? Or even
better, check whether the same packet loss appears when isolating any of such pairs of
nodes so that no batman-adv route changes could happen at all.
For some reason, the spikes disappeared around midnight - and I don't know why.
Maybe batman-adv converged to a different plan (or converged at all) or the Flying
Spaghetti Monster our network to work nowadays.
I'll go one inspecting this issue, but I cannot answer any of your questions. :-(
Keep smiling
yanosz
3802
days inactive
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5 comments
3 participants
participants (3)
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"Linus Lüssing" -
Jan Lühr -
Marek Lindner