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Hi!

We are planning to deploy several VLAN's in the building, but all hosts
should be able to use the same DHCP server. I understand that I can
implement "ip helper", but how then DHCP server knows to which VLAN host
belongs, so that is able to issue the right TCP/IP configuration to that
host (subnet and default gateway particularly)? Any solution except manually
binding TCP/IP settings to hosts MAC addresses in DHCP server configuration?

B.R.
Igor

In article <cdj9q0$r46$>,
says...
> Hi!
>
> We are planning to deploy several VLAN's in the building, but all hosts
> should be able to use the same DHCP server. I understand that I can
> implement "ip helper", but how then DHCP server knows to which VLAN host
> belongs, so that is able to issue the right TCP/IP configuration to that
> host (subnet and default gateway particularly)? Any solution except manually
> binding TCP/IP settings to hosts MAC addresses in DHCP server configuration?
>
> B.R.
> Igor
>
>
>
>

It knows because source sub-interface address is sent in DHCP request
packet proxyed by 'ip helper ...' command. So if you have a range on
DHCP server that matches the address on subinterface, address from that
range will be taken.


--
-Ivan.

*** Use Rot13 to see my eMail address ***

When you say subinterface, you mean subinterface IP address of interVLAN
router? If, so, what if I have ML switch instead of router? Then we 're
talking about SVI IP address? This works on Windows DHCP also?

B.R.
Igor

"Ivan Ostres" <> wrote in message
news: t...
> In article <cdj9q0$r46$>,
> says...
> > Hi!
> >
> > We are planning to deploy several VLAN's in the building, but all hosts
> > should be able to use the same DHCP server. I understand that I can
> > implement "ip helper", but how then DHCP server knows to which VLAN host
> > belongs, so that is able to issue the right TCP/IP configuration to that
> > host (subnet and default gateway particularly)? Any solution except
manually
> > binding TCP/IP settings to hosts MAC addresses in DHCP server
configuration?
> >
> > B.R.
> > Igor
> >
> >
> >
> >
>
> It knows because source sub-interface address is sent in DHCP request
> packet proxyed by 'ip helper ...' command. So if you have a range on
> DHCP server that matches the address on subinterface, address from that
> range will be taken.
>
>
> --
> -Ivan.
>
> *** Use Rot13 to see my eMail address ***

> >
> > It knows because source sub-interface address is sent in DHCP request
> > packet proxyed by 'ip helper ...' command. So if you have a range on
> > DHCP server that matches the address on subinterface, address from that
> > range will be taken.
> >
> >
> > --
> > -Ivan.
> >
> > *** Use Rot13 to see my eMail address ***
>

In article <cdlnvm$9bg$>,
says...
> When you say subinterface, you mean subinterface IP address of interVLAN
> router? If, so, what if I have ML switch instead of router? Then we 're
> talking about SVI IP address? This works on Windows DHCP also?
>
> B.R.
> Igor

Yes, I mean subinterface address on interVLAN router. If you have MLS,
then it's address of SVI. Yes, it works with windows DHCP.

If you need help feel fre to contact me, company I work for provides
consulting on networking & systems in Croatia, and we can do all this
for you.

--
-Ivan.

*** Use Rot13 to see my eMail address ***

[nedalsd]

SO let us say that we have vlan 10 and interface vlan 10 in the mls 10.10.10.1 255.255.255.0
we need any switchport access this vlan 10 to get ip addresses from the domain from this range 10.10.10.10-10.10.10.254
how ip helper can help and where we should apply the command for this vlan?

nedal