Subject: RE: Gratuitous ARP

From: David Whipple <[email-masked]>
Date: Tue, 2 Jun 1998 18:12:04 -0700

Tony,

I think that there are actually quite a few systems which do support
Gratuitous ARP which it does fix.  Two examples were given (NT, and BSD
4.3/4.4).  I am sure that there are many systems which do not support it,
but I am not sure that VRRP was designed to fix these legacy systems.  Maybe
HSRP was...  

Thanks.
David Whipple.

-----Original Message-----
From: Tony Li [mailto:[email-masked]]
Sent: Tuesday, June 02, 1998 5:58 PM
To: David Whipple
Cc: [email-masked]; [email-masked]
Subject: Re: Gratuitous ARP

|  Gratutious ARP is supported on Windows NT, not 9X.  I am not real sure
about
|  which Unix versions support it.

So how does that help the legacy systems that VRRP/HSRP was trying to fix?

Tony

---

From: Tony Li <[email-masked]>
Date: Tue, 2 Jun 1998 18:28:05 -0700 (PDT)

David,

I was asking about systems that do not support router discovery.  New
operating systems that do not support router discovery are clearly simply
flawed.  BSD certainly now supports router discovery.  Does Win98?  NT?

The ENTIRE point of HSRP was to support these legacy systems.  Router
discovery is a clearly better solution in every respect.

I won't claim to understand the technical design goals for VRRP.  The
non-technical ones are obvious.

Tony

|  I think that there are actually quite a few systems which do support
|  Gratuitous ARP which it does fix.  Two examples were given (NT, and BSD
|  4.3/4.4).  I am sure that there are many systems which do not support it,
|  but I am not sure that VRRP was designed to fix these legacy systems.  Maybe
|  HSRP was...  
|  
|  Thanks.
|  David Whipple.
|  
|  -----Original Message-----
|  From: Tony Li [mailto:[email-masked]]
|  Sent: Tuesday, June 02, 1998 5:58 PM
|  To: David Whipple
|  Cc: [email-masked]; [email-masked]
|  Subject: Re: Gratuitous ARP
|  
|  
|  
|  |  Gratutious ARP is supported on Windows NT, not 9X.  I am not real sure
|  about
|  |  which Unix versions support it.
|  
|  So how does that help the legacy systems that VRRP/HSRP was trying to fix?
|  
|  Tony
|

---

From: Acee Lindem <[email-masked]>
Date: Wed, 03 Jun 1998 13:29:28 -0400

> non-technical ones are obvious.

VRRP supports systems which do not support gratuitous ARP just as HSRP does. 
The primary differences are:

   1) VRRP does not require the concept of a virtual IP address. A backup
      router simply takes over forwarding responsibility for hosts having
      the master's IP address as their default gateway address. RFC 2238 
      explains (hopefully, clearly) what that entails. This avoids the 
      problems associated with ICMP redirects and the virtual IP address. 

   2) VRRP runs on link basis rather than an IP subnet basis. Consequently, 
      a single VRID can be used for multiple subnets on the same physical
      network.   

   3) VRRP's authentication encoding is more consistent with other
      protocols (e.g, RIPv2 and OSPF). However, this may be a moot point
      if one is using IPSEC encapsulation. 

-- 
Acee