Possible? eth0:1 ... eth0:50000

Is it possible to have 50000 IP aliases on one
interface in Linux?

If so, what about 2 * 50000 sockets (TCP+UDP)?

If possible, what about up to 10000 processes,
each using 2 * 5 sockets (or 1000 processes with
2 * 50, ...)?

I know, that there are limits in

- Red Hat Linux : 256 IP aliases
- SuSE Linux : 512 (or was it 1024) IP aliases

Is there a kernel parameter (or #define, -D, ...)
to increase the value?

Thanks
Toni


Toni Erdmann

No it is not possible. Max limit is upto 256 aliases per ethX as far as
i knew it.

Toni Erdmann wrote:
> Is it possible to have 50000 IP aliases on one
> interface in Linux?
>
> If so, what about 2 * 50000 sockets (TCP+UDP)?
>
> If possible, what about up to 10000 processes,
> each using 2 * 5 sockets (or 1000 processes with
> 2 * 50, ...)?
>
> I know, that there are limits in
>
> - Red Hat Linux : 256 IP aliases
> - SuSE Linux : 512 (or was it 1024) IP aliases
>
> Is there a kernel parameter (or #define, -D, ...)
> to increase the value?
>
> Thanks
> Toni

--
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of life.

Toni Erdmann wrote:
> Is it possible to have 50000 IP aliases on one
> interface in Linux?

Can't remember the limit offhand -- came across it one time -- and it
was larger than any sensible person would _ever_ need, so forgot about
it. 256?

> If so, what about 2 * 50000 sockets (TCP+UDP)?

See above.

> If possible, what about up to 10000 processes,
> each using 2 * 5 sockets (or 1000 processes with
> 2 * 50, ...)?

See above

> I know, that there are limits in
>
> - Red Hat Linux : 256 IP aliases
> - SuSE Linux : 512 (or was it 1024) IP aliases
>
> Is there a kernel parameter (or #define, -D, ...)
> to increase the value?

That or a source code constant -- else how did Suse ramp it up to a two
byte value?

Even if there were, what Earthly -- or unearthly -- use would you have
for such a beast?

Sounds like maintenance hemorrhoids to me ;-) And only one poor nic to
handle all that traffic :-(

Surely there is a better way to scratch your itch.
regards,
prg
email above disabled

prg wrote:
> Toni Erdmann wrote:
>
>>Is it possible to have 50000 IP aliases on one
>>interface in Linux?
....
>
> Even if there were, what Earthly -- or unearthly -- use would you have
> for such a beast?

Simulating 50000 users who must have (unfortunatelly) each it's
own IP address.

>
> Sounds like maintenance hemorrhoids to me ;-) And only one poor nic to
> handle all that traffic :-(
>

'maintenance' - surely a horror

Thanks
Toni

In comp.os.linux.networking Toni Erdmann <for-spammers-(E-Mail Removed)>:
> Is it possible to have 50000 IP aliases on one
> interface in Linux?

> If so, what about 2 * 50000 sockets (TCP+UDP)?

> If possible, what about up to 10000 processes,
> each using 2 * 5 sockets (or 1000 processes with
> 2 * 50, ...)?

> I know, that there are limits in

> - Red Hat Linux : 256 IP aliases
> - SuSE Linux : 512 (or was it 1024) IP aliases

Did you try this out with recent version and it made sense (not
class C subnet)?

> Is there a kernel parameter (or #define, -D, ...)
> to increase the value?

There have been limits in 2.0/2.2. AFAIK those have gone, a
recent kernel should allow "virtually" unlimited aliases.

Anyway you could write a short script and simply try it or
read up the source, I'd prefer the first, for the fun of it.

--
Michael Heiming (X-PGP-Sig > GPG-Key ID: EDD27B94)
mail: echo (E-Mail Removed) | perl -pe 'y/a-z/n-za-m/'
#bofh excuse 222: I'm not sure. Try calling the Internet's
head office -- it's in the book.

Toni Erdmann wrote:

> Is it possible to have 50000 IP aliases on one
> interface in Linux?

Don't know but you could also try the ip way

ip adress add .....

Andy.


>
> If so, what about 2 * 50000 sockets (TCP+UDP)?
>
> If possible, what about up to 10000 processes,
> each using 2 * 5 sockets (or 1000 processes with
> 2 * 50, ...)?
>
> I know, that there are limits in
>
> - Red Hat Linux : 256 IP aliases
> - SuSE Linux : 512 (or was it 1024) IP aliases
>
> Is there a kernel parameter (or #define, -D, ...)
> to increase the value?
>
> Thanks
> Toni

Michael Heiming <michael+(E-Mail Removed)> wrote:
> In comp.os.linux.networking Toni Erdmann <for-spammers-(E-Mail Removed)>:
>> Is it possible to have 50000 IP aliases on one
>> interface in Linux?

>> If so, what about 2 * 50000 sockets (TCP+UDP)?

>> If possible, what about up to 10000 processes,
>> each using 2 * 5 sockets (or 1000 processes with
>> 2 * 50, ...)?

>> I know, that there are limits in

>> - Red Hat Linux : 256 IP aliases
>> - SuSE Linux : 512 (or was it 1024) IP aliases

> Did you try this out with recent version and it made sense (not
> class C subnet)?

>> Is there a kernel parameter (or #define, -D, ...)
>> to increase the value?

> There have been limits in 2.0/2.2. AFAIK those have gone, a
> recent kernel should allow "virtually" unlimited aliases.

> Anyway you could write a short script and simply try it or
> read up the source, I'd prefer the first, for the fun of it.

Michael is correct as you can see 2**32=4294967296

# uname -a
Linux test 2.4.26 #1 Sat Nov 27 08:38:10 CST 2004 sparc unknown
# ifconfig eth0:4294967296 10.0.2.15 up
# ifconfig -a
eth0 Link encap:Ethernet HWaddr 08:00:20:79:89:46
inet addr:192.168.0.254 Bcast:192.168.0.255
Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:5899251 errors:0 dropped:0 overruns:0 frame:0
TX packets:6293965 errors:1 dropped:0 overruns:0 carrier:1
collisions:23782 txqueuelen:1000
RX bytes:1128214406 (1.0 GiB) TX bytes:2027006570 (1.8 GiB)
Interrupt:38

eth0:4294 Link encap:Ethernet HWaddr 08:00:20:79:89:46
inet addr:10.0.2.15 Bcast:10.255.255.255 Mask:255.0.0.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Interrupt:38

# ifconfig eth0:4294 down
SIOCSIFFLAGS: Cannot assign requested address
# ifconfig eth0:4294967296 down
#

You just need a better "ifconfig" command so that it does not truncate
the alias.

Andy Furniss schrieb:
> Toni Erdmann wrote:
>
>
>>Is it possible to have 50000 IP aliases on one
>>interface in Linux?
>
>
> Don't know but you could also try the ip way
>
> ip adress add .....
>
> Andy.
>

Did it and it seems to work. Tried 4000 adresses.

next step will be:

Perl script:

for-loop oder 64000
{
$IP_address = ... some code ...
$resp = `ip addr add $IP_address.....`;

socket(.....)
bind(..., $IP_address, ...)
...
}

to see the limits with
- IP addresses
- sockets
- file descriptors
- ...

Thanks
Toni

Alex_Yung/id=alyung schrieb:
> Michael Heiming <michael+(E-Mail Removed)> wrote:
>
>>In comp.os.linux.networking Toni Erdmann <for-spammers-(E-Mail Removed)>:
>>
....
> You just need a better "ifconfig" command so that it does not truncate
> the alias.

I tried "ip addr add ..."

see other posting in same group.

Toni

Michael Heiming wrote
> In comp.os.linux.networking Toni Erdmann <for-spammers-(E-Mail Removed)>:
>
....
> Anyway you could write a short script and simply try it or
> read up the source, I'd prefer the first, for the fun of it.
>

Yes, will do that. See other posting in same thread.

Toni