20 Nov
2007
20 Nov
'07
5:22 a.m.
Hi,
starting batmand, the daemon sometimes doesn't seem to recognize the
network the right way.
root@25:~# killall batmand
root@25:~# batmand eth1:1 vlan0:1
Using interface eth1:1 with address 192.168.42.25 and broadcast address
192.168.43.255
Using interface vlan0:1 with address 192.168.42.25 and broadcast address
192.168.43.255
-------------------------------------------------------
This is a tcpdump from a neighbor node:
root@ap14:~# tcpdump -i eth0 src 192.168.42.25
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
05:12:09.512310 arp who-has 192.168.43.255 tell 192.168.42.25
05:12:10.512178 arp who-has 192.168.43.255 tell 192.168.42.25
05:12:11.699795 arp who-has 192.168.43.255 tell 192.168.42.25
-------------------------------------------
on the other node:
root@25:~# killall batmand
root@25:~# batmand eth1:1 vlan0:1
Using interface eth1:1 with address 192.168.42.25 and broadcast address
192.168.43.255
Using interface vlan0:1 with address 192.168.42.25 and broadcast address
192.168.43.255
root@25:~#
----------------------------------------------
tcpdump:
05:12:28.621940 IP 192.168.42.25.4305 > 192.168.43.255.4305: UDP, length 20
05:12:28.873246 IP 192.168.42.25.4305 > 192.168.43.255.4305: UDP, length 25
05:12:28.892343 IP 192.168.42.25.4305 > 192.168.43.255.4305: UDP, length 15
now batmand is running successfully.
Any Ideas?
regards,
Rene
20 Nov
20 Nov
9:08 a.m.
Hi,
On Dienstag 20 November 2007, rene wrote:
Hi,
starting batmand, the daemon sometimes doesn't seem to recognize the
network the right way.
root@25:~# killall batmand
root@25:~# batmand eth1:1 vlan0:1
Using interface eth1:1 with address 192.168.42.25 and broadcast address
192.168.43.255
Using interface vlan0:1 with address 192.168.42.25 and broadcast address
192.168.43.255
-------------------------------------------
on the other node:
root@25:~# killall batmand
root@25:~# batmand eth1:1 vlan0:1
Using interface eth1:1 with address 192.168.42.25 and broadcast address
192.168.43.255
Using interface vlan0:1 with address 192.168.42.25 and broadcast address
192.168.43.255
root@25:~#
What is definitively not correct is that your capture indicates 4 times the
same IP address (192.168.42.25) on 4 different interfaces.
Can you check whether your capture, the alias-interface configuration (what is
the output of ip a ?), or the daemon is wrong?
There MUST be a different IP address for each BATMAN interface in the network
(also if a single BATMAN node has more than one interface).
All BATMAN interfaces SHOULD have the same netmask and broadcast address.
ciao,
axel
10:31 a.m.
Hi,
Axel Neumann wrote:
Hi,
On Dienstag 20 November 2007, rene wrote:
This is two times the
same node, first time it recognizes the broadcast
the right way, second time not.
Hi,
starting batmand, the daemon sometimes doesn't seem to recognize the
network the right way.
root@25:~# killall batmand
root@25:~# batmand eth1:1 vlan0:1
Using interface eth1:1 with address 192.168.42.25 and broadcast address
192.168.43.255
Using interface vlan0:1 with address 192.168.42.25 and broadcast address
192.168.43.255
-------------------------------------------
on the other node:
root@25:~# killall batmand
root@25:~# batmand eth1:1 vlan0:1
Using interface eth1:1 with address 192.168.42.25 and broadcast address
192.168.43.255
Using interface vlan0:1 with address 192.168.42.25 and broadcast address
192.168.43.255
root@25:~#
What is definitively not correct is that your capture indicates 4 times the
same IP address (192.168.42.25) on 4 different interfaces. There MUST be a different IP address for each BATMAN
interface in the network
(also if a single BATMAN node has more than one interface).
Is this implemented
like this (where?)? Can't work BATMAN with the
interfaces (or can't we change it to work this way), it would make the
whole configuration much easier to assign to every node only one single
IP address (or two, one for olsr and ne for BATMAN)? We are doing this
with olsr and this really makes the network-structure much cleaner -
every node has one IP.
Is the described problem with the misconfigured broadcast related to the
'same IP on different interfaces' issue?
regards,
Rene
10:59 a.m.
New subject: [B.A.T.M.A.N.] single IP for multiple interfaces (was: Re: [B.A.T.M.A.N.] problem starting batmand (v799))
Hi,
05:12:09.512310 arp who-has 192.168.43.255 tell
192.168.42.25
05:12:10.512178 arp who-has 192.168.43.255 tell 192.168.42.25
These ARP request are not issued by BATMAN itself. BATMAN does only send
broadcast packets - your system creates these requests.
This is two times the same node, first time it
recognizes the broadcast
the right way, second time not.
BATMAN askes the system for the IP and broadcast addresses. In both cases the
system responds with the same answer. I don't see much difference from
batmans point of view.
Is this implemented like this (where?)? Can't work
BATMAN with the
interfaces (or can't we change it to work this way), it would make the
whole configuration much easier to assign to every node only one single
IP address (or two, one for olsr and ne for BATMAN)? We are doing this
with olsr and this really makes the network-structure much cleaner -
every node has one IP.
You have multihomed OLSR nodes with a single IP and that works ? Can anyone of
the OLSR folks say something about that ? I can't imagine how the routing
daemon can distinguish 2 distinct connections with the same address ...
Regards,
Marek
11:29 a.m.
New subject: [B.A.T.M.A.N.] single IP for multiple interfaces
Hi,
Marek Lindner wrote:
Hi,
But thats definitely whats happening, on OpenWrt WRAP (x86)
as well as
on BroadCom (mipsel). It happened more than once, and the only thing
what was done to change the behavior was killing and starting batmand
again. Which doesn't changed every time the behavior.
05:12:09.512310 arp who-has 192.168.43.255 tell
192.168.42.25
05:12:10.512178 arp who-has 192.168.43.255 tell 192.168.42.25
These ARP request are not issued by BATMAN itself. BATMAN does only send
broadcast packets - your system creates these requests.
This is two times the same node, first time it
recognizes the broadcast
the right way, second time not.
BATMAN askes the system for the IP and broadcast addresses. In both cases the
system responds with the same answer. I don't see much difference from
batmans point of view. You have multihomed OLSR nodes with a single IP and
that works ? Can anyone of
the OLSR folks say something about that ? I can't imagine how the routing
daemon can distinguish 2 distinct connections with the same address ...
Works
perfect, we use for instance the WRAP-boards in our network with
two WIFI- and one LAN-Interface, all three having the same IP.
The related patch is at
http://titan.www.opennet-initiative.de/olsrd_patches/mipip.patch, but
its since a while part of olsrd.
Regards,
Rene
11:32 a.m.
Hello,
On Dienstag 20 November 2007, rene wrote:
Yes it is implemented/designed like this.
It operates on layer three and
above. IP addresses are used to differentiate between different links to the
same neighbors. For example two nodes A and B, each with two wireless
interfaces 1 and 2. All interfaces operating in the same channel, bssid, ...
How could node A differentiate between the link A1<->B1 and A1<->B2 if it is
not aware of any MAC addresses. But even if it is aware of MAC addresses. How
could it set up the routing table to ensure that a packet to a distant node C
should be routed via B1 (and NOT via B2)?
Hi,
Axel Neumann wrote:
of course, ive been somwhow distracted by "the
other node"
Hi,
On Dienstag 20 November 2007, rene wrote:
This is two times the same node, first time it recognizes the broadcast
the right way, second time not. Hi,
starting batmand, the daemon sometimes doesn't seem to recognize the
network the right way.
root@25:~# killall batmand
root@25:~# batmand eth1:1 vlan0:1
Using interface eth1:1 with address 192.168.42.25 and broadcast address
192.168.43.255
Using interface vlan0:1 with address 192.168.42.25 and broadcast address
192.168.43.255
-------------------------------------------
on the other node:
root@25:~# killall batmand
root@25:~# batmand eth1:1 vlan0:1
Using interface eth1:1 with address 192.168.42.25 and broadcast address
192.168.43.255
Using interface vlan0:1 with address 192.168.42.25 and broadcast address
192.168.43.255
root@25:~#
What is definitively not correct is that your capture indicates 4 times
the same IP address (192.168.42.25) on 4 different interfaces. There MUST be a different IP address for each
BATMAN interface in the
network (also if a single BATMAN node has more than one interface).
Is this implemented like this (where?)? Can't work BATMAN with the
interfaces (or can't we change it to work this way)
i guess its not that easy
but if you are familiar with protocol design and c
coding go ahead...
Or you take a look on batman-advanced, but thats another story :-)
, it would make the
whole configuration much easier to assign to every node only one single
IP address (or two, one for olsr and ne for BATMAN)? We are doing this
with olsr and this really makes the network-structure much cleaner -
every node has one IP.
Actually, I did not even know that this is possible - is such a configuration
proposed somewhere. I can imagine that this somehow works but how shure are
you that this does not introduce any negative side effects?
ciao,
axel
Is the described problem with the misconfigured broadcast related to the
'same IP on different interfaces' issue?
regards,
Rene
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11:39 a.m.
New subject: [B.A.T.M.A.N.] single IP for multiple interfaces
Hi,
Axel Neumann wrote:
Yes it is implemented/designed like this. It
operates on layer three and
above. IP addresses are used to differentiate between different links to the
same neighbors. For example two nodes A and B, each with two wireless
interfaces 1 and 2. All interfaces operating in the same channel, bssid, ...
How could node A differentiate between the link A1<->B1 and A1<->B2 if it is
not aware of any MAC addresses. But even if it is aware of MAC addresses. How
could it set up the routing table to ensure that a packet to a distant node C
should be routed via B1 (and NOT via B2)? just by setting the interface to the way
the package has to leave the
node? Just the same way olsr does, I'm not a protocol designer but don't
see any main reason why Batman shouldn't be possible to do it similar.
There MUST be a different IP address for each BATMAN
interface in the
network (also if a single BATMAN node has more than one interface).
Is this
implemented like this (where?)? Actually, I did not even know that this is possible -
is such a configuration
proposed somewhere. I can imagine that this somehow works but how shure are
you that this does not introduce any negative side effects?
We are using this in
Rostock since a while (on all WRAPs and on selected
APs) and it works very well. Side effects? Maybe, you never know for
sure, none recognized and I'm not deep enough into protocol designs to
answer this from a theoretical point of view. But it's a great feature
which makes Mesh networking much easier and the whole structure much
cleaner.
Regards,
Rene
12:24 p.m.
New subject: [B.A.T.M.A.N.] single IP for multiple interfaces
Hi,
Works perfect, we use for instance the WRAP-boards in
our network with
two WIFI- and one LAN-Interface, all three having the same IP.
The related patch is at
http://titan.www.opennet-initiative.de/olsrd_patches/mipip.patch, but
its since a while part of olsrd.
I read the patch and without knowing the olsrd code I would say that you
operate on interface names instead of IPs. But I see some problems here:
- How does this work in a mixed environment ?
- More important: The routing table operates on IP addresses and not on
interface names. Even if olsrd can distinguish your interfaces by name the
kernel can't.
Imagine: You have a node A with 2 Interfaces and node B can hear both
interfaces but one better than the other. The routing table entry would look
like that "<destination> via IP_of_node_A" whereas the kernel can't
send the
packet to a distinct interface of A. Whatever interface of A responds first
to your ARP query will get all data packets and thus you may end up with
using lossy links.
I don't see anything to solve that in this patch.
Regards,
Marek
12:31 p.m.
New subject: [B.A.T.M.A.N.] single IP for multiple interfaces
On Dienstag 20 November 2007, rene wrote:
Hi,
Axel Neumann wrote:
Yes it is implemented/designed like this. It operates on layer three and
above. IP addresses are used to differentiate between different links to
the same neighbors. For example two nodes A and B, each with two wireless
interfaces 1 and 2. All interfaces operating in the same channel, bssid,
... How could node A differentiate between the link A1<->B1 and A1<->B2
if it is not aware of any MAC addresses. But even if it is aware of MAC
addresses. How could it set up the routing table to ensure that a packet
to a distant node C should be routed via B1 (and NOT via B2)?
just by setting the interface to the way the package has to leave the
node? Just the same way olsr does, I'm not a protocol designer but don't
see any main reason why Batman shouldn't be possible to do it similar.
IMO that does only work if the interfaces of a node are NOT connected to the
same physical/logical link (e.g. B1 and B2 are operating on different
channels or with different cell IDs,...). Otherwise specifying the outgoing
interface is not enough. Even if node A has only one interface (A1). If there
is a link A1<->B1 and a link A1<->B2 the problem remains:
There MUST be a different IP address for each BATMAN
interface in the
network (also if a single BATMAN node has more than one interface).
Is this implemented like this (where?)? > How could it set up the routing table to ensure
that a packet
> to a distant node C should be routed via B1 (and NOT via B2)?
The outgoing
interface of node A is A1, for both cases. Setting the outgoing
interface to A1 has no effect.
Maybe there is a way to configure the next-hop-mac address instead of the
next-hop-ip address. But then you rather have layer 2 routing and not layer
3.
/axel
Actually, I did not even know that this is
possible - is such a
configuration proposed somewhere. I can imagine that this somehow works
but how shure are you that this does not introduce any negative side
effects?
We are using this in Rostock since a while (on all WRAPs and on selected
APs) and it works very well. Side effects? Maybe, you never know for
sure, none recognized and I'm not deep enough into protocol designs to
answer this from a theoretical point of view. But it's a great feature
which makes Mesh networking much easier and the whole structure much
cleaner.
Regards,
Rene
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B.A.T.M.A.N mailing list
B.A.T.M.A.N(a)open-mesh.net
https://list.open-mesh.net/mm/listinfo/b.a.t.m.a.n
1:45 p.m.
New subject: [B.A.T.M.A.N.] single IP for multiple interfaces
Hi,
Marek Lindner wrote:
- More important: The routing table operates on IP
addresses and not on
interface names. Even if olsrd can distinguish your interfaces by name the
kernel can't.
sure? (I'm in no way an expert, its an honest question.)
root@OpenWrt:~# ip route
192.168.1.48 via 192.168.1.188 dev ath1 metric 7
192.168.2.40 via 192.168.1.188 dev ath1 metric 6
192.168.1.49 via 192.168.1.188 dev ath1 metric 4
192.168.2.42 via 192.168.1.188 dev ath1 metric 7
192.168.1.51 via 192.168.2.172 dev eth0 metric 2
192.168.1.53 via 192.168.1.188 dev ath1 metric 6
192.168.1.56 via 192.168.1.188 dev ath1 metric 6
192.168.2.32 via 192.168.1.188 dev ath1 metric 7
192.168.1.57 via 192.168.1.188 dev ath1 metric 6
192.168.2.33 via 192.168.1.188 dev ath1 metric 8
192.168.1.58 via 192.168.1.188 dev ath1 metric 3
192.168.1.60 via 192.168.1.188 dev ath1 metric 7
....
so there are interfaces shown in the routes, the kernel should recognize
them, what else they are for?
Imagine: You have a node A with 2 Interfaces and node
B can hear both
interfaces but one better than the other. The routing table entry would look
like that "<destination> via IP_of_node_A" whereas the kernel can't
send the
packet to a distinct interface of A.
see above...
regards,
Rene
PS: Invited Sebastian Hagen who programmed the patch to join the
discussion, hope he will help me/us with more details
2:08 p.m.
New subject: [B.A.T.M.A.N.] single IP for multiple interfaces
sure? (I'm in no way an expert, its an honest
question.)
root@OpenWrt:~# ip route
192.168.1.48 via 192.168.1.188 dev ath1 metric 7
192.168.2.40 via 192.168.1.188 dev ath1 metric 6
192.168.1.49 via 192.168.1.188 dev ath1 metric 4
192.168.2.42 via 192.168.1.188 dev ath1 metric 7
192.168.1.51 via 192.168.2.172 dev eth0 metric 2
so there are interfaces shown in the routes, the
kernel should recognize
them, what else they are for?
As Axel already mentionned: These are the outgoing interfaces which you can
specify but the problem arises if your neighbor node has 2 interfaces as
well. How are you going to seperate these ? Normally you do so by using 2
different IP addresses to send traffic to one or the other interface. But if
you only have one address ...
PS: Invited Sebastian Hagen who programmed the patch
to join the
discussion, hope he will help me/us with more details
Good idea. :-)
Greetings,
Marek
5671
days inactive
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days old
b.a.t.m.a.n@lists.open-mesh.org
10 comments
3 participants
participants (3)
-
Axel Neumann -
Marek Lindner -
rene