Re: [c-nsp] Setting relay agent IP on 4500

2017-08-04 Thread Jason Lixfeld
> On Aug 4, 2017, at 11:31 AM, Phil Mayers wrote: > > On 04/08/2017 16:05, Jason Lixfeld wrote: > >> ip dhcp relay information option vpn >> ip dhcp compatibility suboption link-selection standard > > That's useful to know - TBH I wasn't even aware this setup was

Re: [c-nsp] Setting relay agent IP on 4500

2017-08-04 Thread Phil Mayers
On 04/08/2017 16:05, Jason Lixfeld wrote: ip dhcp relay information option vpn ip dhcp compatibility suboption link-selection standard That's useful to know - TBH I wasn't even aware this setup was supported on routers, it has been a long time since I've looked at it. Have you tested to

Re: [c-nsp] Setting relay agent IP on 4500

2017-08-04 Thread Jason Lixfeld
> On Aug 4, 2017, at 3:57 AM, Phil Mayers wrote: > > On 03/08/17 21:27, Jason Lixfeld wrote: >> >>> On Jul 31, 2017, at 12:17 PM, Phil Mayers wrote: >>> >>> I guess you could use a dummy relay that added a fake RFC3527 option but >>> yuck...

Re: [c-nsp] Setting relay agent IP on 4500

2017-08-04 Thread Phil Mayers
On 03/08/17 21:27, Jason Lixfeld wrote: On Jul 31, 2017, at 12:17 PM, Phil Mayers wrote: I guess you could use a dummy relay that added a fake RFC3527 option but yuck... What do you mean by this, exactly? Relay to a relay? Didn’t think that was possible because

Re: [c-nsp] Setting relay agent IP on 4500

2017-08-03 Thread Jason Lixfeld
> On Jul 31, 2017, at 12:17 PM, Phil Mayers wrote: > > I guess you could use a dummy relay that added a fake RFC3527 option but > yuck... What do you mean by this, exactly? Relay to a relay? Didn’t think that was possible because a relay only accepts broadcasts…

Re: [c-nsp] Setting relay agent IP on 4500

2017-07-31 Thread Phil Mayers
On 31/07/17 17:13, Jason Lixfeld wrote: I am assuming that IOS does not do this on a "global" IP helper, then? No. My impression is that the “global" argument just tells the relay that the server is not in a VRF (either the one configured in the That's been my experience (but as noted, we

Re: [c-nsp] Setting relay agent IP on 4500

2017-07-31 Thread Jason Lixfeld
> On Jul 31, 2017, at 11:57 AM, Phil Mayers wrote: > > On 31/07/17 15:38, Jason Lixfeld wrote: > >> Agreed. However, if the relay is configured to use option 82 sub option 5 >> (RFC3527), the relay can overwrite the giaddr to an IP that is reachable by >> the DHCP

Re: [c-nsp] Setting relay agent IP on 4500

2017-07-31 Thread Phil Mayers
On 31/07/17 15:38, Jason Lixfeld wrote: Agreed. However, if the relay is configured to use option 82 sub option 5 (RFC3527), the relay can overwrite the giaddr to an IP that is reachable by the DHCP server (typically the egress interface instead of the ingress interface). The relay would

Re: [c-nsp] Setting relay agent IP on 4500

2017-07-31 Thread Jason Lixfeld
> On Jul 29, 2017, at 8:43 AM, Nathan Lannine wrote: > >>> The issue is the 4500 stamps the relay agent IP in the DISCOVER as >>> being the incoming interface IP where the DISCOVER was received, > > Yeah, that's expected and required behavior. I sort of assumed, as >

Re: [c-nsp] Setting relay agent IP on 4500

2017-07-31 Thread Jason Lixfeld
> On Jul 29, 2017, at 4:12 AM, Phil Mayers wrote: > > On 28/07/17 22:12, Jason Lixfeld wrote: >> Hi all, >> >> I’ve got a 4500 Sup7L-E running 15.2(2) acting as a DHCP relay with >> clients directly connected to it. The client interfaces on this >> relay are in VRFs,

Re: [c-nsp] Setting relay agent IP on 4500

2017-07-29 Thread Phil Mayers
On 29/07/17 13:43, Nathan Lannine wrote: The issue is the 4500 stamps the relay agent IP in the DISCOVER as being the incoming interface IP where the DISCOVER was received, Yeah, that's expected and required behavior. I sort of assumed, as Mr. Mayer indicated, that the "global" option would

Re: [c-nsp] Setting relay agent IP on 4500

2017-07-29 Thread Nathan Lannine
>> The issue is the 4500 stamps the relay agent IP in the DISCOVER as >> being the incoming interface IP where the DISCOVER was received, Yeah, that's expected and required behavior. I sort of assumed, as Mr. Mayer indicated, that the "global" option would still set the giaddr to the receiving

Re: [c-nsp] Setting relay agent IP on 4500

2017-07-29 Thread Phil Mayers
On 28/07/17 22:12, Jason Lixfeld wrote: Hi all, I’ve got a 4500 Sup7L-E running 15.2(2) acting as a DHCP relay with clients directly connected to it. The client interfaces on this relay are in VRFs, and the helper is in the global table. The issue is the 4500 stamps the relay agent IP in the

Re: [c-nsp] Setting relay agent IP on 4500

2017-07-28 Thread Jason Lixfeld
Nope. That's how it's configured already. No Dice. Sent from my iPhone > On Jul 28, 2017, at 9:34 PM, Nathan Lannine wrote: > > > > On Jul 28, 2017 5:12 PM, "Jason Lixfeld" wrote: > Hi all, > > I’ve got a 4500 Sup7L-E running 15.2(2) acting as

Re: [c-nsp] Setting relay agent IP on 4500

2017-07-28 Thread Nathan Lannine
On Jul 28, 2017 5:12 PM, "Jason Lixfeld" wrote: Hi all, I’ve got a 4500 Sup7L-E running 15.2(2) acting as a DHCP relay with clients directly connected to it. The client interfaces on this relay are in VRFs, and the helper is in the global table. The issue is the 4500 stamps

[c-nsp] Setting relay agent IP on 4500

2017-07-28 Thread Jason Lixfeld
Hi all, I’ve got a 4500 Sup7L-E running 15.2(2) acting as a DHCP relay with clients directly connected to it. The client interfaces on this relay are in VRFs, and the helper is in the global table. The issue is the 4500 stamps the relay agent IP in the DISCOVER as being the incoming