| |
PA2AGA > TCPDIG 16.02.97 20:26l 193 Lines 7712 Bytes #-10719 (0) @ EU
BID : TCP_97_18
Read: DG7DAH GUEST
Subj: TCP-Group Digest 97/18
Path: DB0AAB<DB0PV<DB0WGS<OE3XSR<OK0PBX<OK0PBB<OK0PAB<OH3RBR<OH2RBI<OH7RBA<
PI8VNW
Sent: 970216/1455Z @:PI8VNW.#ZH2.NLD.EU #:41927 [Hoek v Holland] FBB5.15c
From: PA2AGA@PI8VNW.#ZH2.NLD.EU
To : TCPDIG@EU
Received: from pa2aga by pi1hvh with SMTP
id AA29015 ; Sun, 16 Feb 97 14:38:33 UTC
Received: from pa2aga by pa2aga (NET/Mac 2.3.62/7.1) with SMTP
id AA00001614 ; Sun, 16 Feb 97 15:22:17 MET
Received: from pa2aga-1 by pa2aga with SMTP
id AA00001613 ; Sun, 16 Feb 97 15:09:23 MET
Received: from pa2aga-1 by pa2aga-1 (NET/Mac 2.3.62/7.6) with SMTP
id AA00009162 ; Sun, 16 Feb 97 15:08:53 MET
Date: Sun, 16 Feb 97 15:00:35 MET
Message-Id: <tcp_97_18>
From: pa2aga
To: tcp_broadcast@pa2aga-1
Subject: TCP-Group Digest 97/18
X-BBS-Msg-Type: B
TCP-Group Digest Sun, 16 Feb 97 Volume 97 : Issue 18
Today's Topics:
One ip address for each interface. (3 msgs)
tcpip
Send Replies or notes for publication to: <TCP-Group@UCSD.Edu>.
Subscription requests to <TCP-Group-REQUEST@UCSD.Edu>.
Problems you can't solve otherwise to brian@ucsd.edu.
Archives of past issues of the TCP-Group Digest are available
(by FTP only) from ftp.UCSD.Edu in directory "mailarchives".
We trust that readers are intelligent enough to realize that all text
herein consists of personal comments and does not represent the official
policies or positions of any party. Your mileage may vary. So there.
----------------------------------------------------------------------
Date: Sat, 15 Feb 1997 19:05:57 +0100 (MET)
From: Julian Munoz <julian@nos.ea4rct.ampr.org>
Subject: One ip address for each interface.
Hello to everybody,
I see the list is a little "alone", I hope that doesn't mean that new
generations don't worry about ip and (posible) feature.
I suppose this topic has been approached (long time ago) in this list. I
still don't know the answer. Is it "correct" to have a linux or a jnos
with 2 ports with the same ip and the same netmask ?? Is there an rfc
about that ??
Thanks !!
Saludos de Julian Amateur Radio Operator License: EA n 53-37081-VI
@ EA4ABB
------------------------------
Date: Sat, 15 Feb 1997 20:02:51 GMT
From: brian@nothing.ucsd.edu (Brian Kantor)
Subject: One ip address for each interface.
Two ports may have the same address if
1) they are on the same physical network and are being used for
load sharing (i.e., you don't need to tell them apart, you're
just trying to get more bandwidth out of them somehow) and they
have the same physical address or do proxy arp
or
2) one of them is a point-to-point link running in 'unnumbered'
mode - such as PPP (where the interface really doesn't have an
address but assumes the address of e.g., the ethernet interface
of the PPP-connected machine.
Note that both of these are rare use of interfaces in this way. In almost
all other applications, each interface will have its own address.
Unfortunately, in the ham world, a lot of people want to do IP routing
between different frequencies and assign separate addresses to each,
since on first thought that seems the best way to go. The immediate
implication of this is that every frequency in an area has to be a
separate subnet, and you have to change addresses every time you change
frequencies, and there has to be routers between all the freqs.
Better to treat the whole area as one subnet and use AX.25 routing to
select which interface to send a packet - i.e, the interface is chosen
from information in the 'wiretap' and/or 'arp' tables. I don't think
any of the ham software packages do this yet.
What we do here in the San Diego central IP switch is assume a default
route of the interface that lives on the 144.76/145.36 packet repeater,
and use broadcast unsolicited ARP responses to override that default
for specific stations who are operating on other frequencies.
- Brian
------------------------------
Date: Sun, 16 Feb 1997 11:08:07 +0100
From: Simon J Mudd <sjmudd@phoenix.ea4els.ampr.org>
Subject: One ip address for each interface.
In article <199702152002.UAA26631@nothing.ucsd.edu>, Brian wrote:
> Two ports may have the same address if
[2 good reasons for using the same ip address]
>
> Note that both of these are rare use of interfaces in this way. In almost
> all other applications, each interface will have its own address.
>
> Unfortunately, in the ham world, a lot of people want to do IP routing
> between different frequencies and assign separate addresses to each,
> since on first thought that seems the best way to go. The immediate
> implication of this is that every frequency in an area has to be a
> separate subnet, and you have to change addresses every time you change
> frequencies, and there has to be routers between all the freqs.
Presumably those who are using ip routing use routed or rspfd because it
exists, and because it works. Presumably over the potentially highly
unreliable links we have these protocols may have deficiencies?
(A question as I think they were designed for reliable networks)
> Better to treat the whole area as one subnet and use AX.25 routing to
> select which interface to send a packet - i.e, the interface is chosen
> from information in the 'wiretap' and/or 'arp' tables. I don't think
> any of the ham software packages do this yet.
I had been thinking of this. this sounds like a proxy arp daemon which
will broadcast on receiving an ARP REQUEST replying with it's own AX25
hardware address. Potentially the station making the ARP REQUEST could
receive more than one answer. Which one would it choose? The proxy arp
daemon would need to update it's tables dynamically removing hosts it
can't hear after a certain period of time. This sounds like the function
used by ethernet bridges. Does software for this exist, or is this
similar to the functionality existed by other software for other "network
types"?
> What we do here in the San Diego central IP switch is assume a default
> route of the interface that lives on the 144.76/145.36 packet repeater,
> and use broadcast unsolicited ARP responses to override that default
> for specific stations who are operating on other frequencies.
this is what we do in Madrid, with only a few hosts, but it does not seem
very dynamic, and presumably for two hosts active on more than one
band there is only one route between them on one of the bands. I guess
ideally here the type of activity of the load balancing for multiple
ppp-connections available in the linux kernel might be useful if that
funcionality were availalbe, even allowing "load balancing" between different
links of different speeds. Does the linux stuff cope with line speeds which
are different?
the big question here seems to be "route at ip level" or route a "ax25 level".
My networking knowledge is very limited. Are the any reasons to prefer one
level over the other, apart from requiring multiple ip addresses if routing
at the ip level between different hosts in different bands?
--
regards,
Simon J Mudd, EA4ELS / G0FNB +34-1-559 2854 Madrid, Spain
sjmudd@redestb.es
ea4els@phoenix.ea4els.ampr.org [short messages - radio hams only]
------------------------------
Date: Sat, 15 Feb 1997 19:18:21 -0600
From: Mike Nettles <miken@insolwwb.net>
Subject: tcpip
add tcp-group
--
Mike Nettles KB5WBH
http://www.insolwwb.net/~miken
http://pager.blyonline.com/~mcara
------------------------------
End of TCP-Group Digest V97 #18
******************************
You can send your message for this bulletin
to: tcp-group@pa2aga on .AMPR.ORG-net
or: tcpaga@pi8vnw.#zh2.nld.eu on BBS-net
------
NOT TO: pa2aga@pa2aga or pa2aga@pi8vnw.#zh2.nld.eu PLEASE!!
It will get posted automatically within a few days
Read previous mail | Read next mail
| |
