From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <51C77678.1040904@altermundi.net> Date: Sun, 23 Jun 2013 19:28:08 -0300 From: Gui Iribarren MIME-Version: 1.0 References: <51C76DDE.20903@altermundi.net> In-Reply-To: <51C76DDE.20903@altermundi.net> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [B.A.T.M.A.N.] Possible bad interaction between BLA2 and TT? Reply-To: The list for a Better Approach To Mobile Ad-hoc Networking List-Id: The list for a Better Approach To Mobile Ad-hoc Networking List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: The list for a Better Approach To Mobile Ad-hoc Networking On 06/23/2013 06:51 PM, Gui Iribarren wrote: > Hey everyone! > fiiinally got back home, a week ago, and got time to debug a strange > issue here. The report i had from a few users was "intermittent > connectivity", with "waves" of traffic, with random pauses lasting from > a few seconds to a minute or so. > > I initially dismissed as interference, or even OS problems, but turns > out they were right! and sadly, batman seems to be in the way > > From what i've seen, watching "batctl tg -w" on every node along the > way, i could determine the window of time where the traffic gets lost: > from the moment when there's a TT change on one side of the network, > to the moment that change is propagated to the other side. > > By ordex's advice, i ran some "batctl ll tt ; batctl l" along the way > and i'm sending the pastebin results at the end of this mail. > > Some (hopefully) useful context follows, and a batctl vd graph is attached > > The IPv6 of tdorado is pinged (to rule out DAT interactions) from > labanda-este (works fine always) and from labanda-oeste (suffers the > issue, as well as all nodes "behind" it, i.e. casapuente & alfredo). > both labandas are tl-wdr3500 connected by 2.4ghz, 5ghz, and an ethernet > cable. The ethernet carries only batadv packets (eth0.1 is added to > bat0); there's no "lan backbone" (the eth0.2 that appears under br-lan > is not connected to anything) > > root@tdorado:~# opkg list kmod-batman-adv # same in all nodes > kmod-batman-adv - 3.8.3+2013.2.0-2 > root@tdorado:~# ip a s br-lan > 6: br-lan: mtu 1500 qdisc noqueue > state UP > link/ether 64:70:02:3d:a0:f7 brd ff:ff:ff:ff:ff:ff > inet6 2a00:1508:1:f004:6670:2ff:fe3d:a0f7/64 scope global dynamic > valid_lft 6985sec preferred_lft 6985sec > root@tdorado:~# batctl tl -n |grep f7 > * 64:70:02:3d:a0:f7 [.....] 1.140 > root@tdorado:~# batctl o |head -n 1 > [B.A.T.M.A.N. adv 2013.2.0, MainIF/MAC: wlan0-1/66:70:02:3d:a0:f9 (bat0)] > > labanda-este > http://pastebin.com/R1kHQCQG > > labanda-oeste > http://pastebin.com/b1Uc23VZ > > Both ping6s were started at the same time, so the seq numbers are > synchronized, and can be used as timestamps. > > the "gap" in labanda-oeste is between seq=73 and seq=89 > in labanda-oeste there were no messages or traffic for 25secs, and then > the "TT inconsistency" came up, resolved, and seq=89 succeded, traffic > restored. > at that time, seq=74, labanda-este got a TT update: > [ 23161800] Deleting tdorado from global tt entry 44:d8:84:b0:d2:f5: tt > removed by changes > and (AFAIU) dropped traffic coming from labanda-oeste until > labanda-oeste finally got the TT update and increased the ttvn to 129 To clarify, what i mean is that during the time window that packets from labanda-oeste get lost, i see this root@labanda-este:~# batctl tg |grep tdorado_eth0 * tdorado_eth0 ( 0) via tdorado ( 77) (0xe574) [...] root@labanda-oeste:~# batctl tg|grep tdorado_eth0 * tdorado_eth0 ( 75) via tdorado ( 76) (0x03db) [...] and traffic is restored the instant oeste gets ttvn=77 / crc=0xe574 finally, i must add that running a "batctl ping tdorado" from labanda-oeste in parallel shows no loss during the whole scenario. > > does any of this make sense? I imagine a tcpdump would help, so i'll try > getting one, but maybe this debug was enough to get an insight? > > As you can imagine, any further pointer will be greatly appreciated, > > I hope you're having a great week, ...and that i'm not ruining it as > always :D > > Gui