Setting the "other-config-flag" or O-bit on a Cisco ASA

Jim Kirby jkirby at
Fri Mar 25 15:52:31 CET 2011

Another point to consider is that any ASA shipped before 2/10/2010 will require a significant DRAM upgrade and possibly an internal flash upgrade in order to run anything newer than 8.3 (the latest is 8.4.x).
Jim Kirby
Director of Engineering
Dataware Services
main: 605.336.0820 x368  
fax:  605.336.0228

On Mar 24, 2011, at 1:39 PM, Frank Bulk - wrote:

> Good point.  But changing a customer's network topology to get IPv6 support
> is not a winning approach.  Hopefully Cisco can surprise us and get that
> feature put in earlier rather than later.  We have quite a few customers
> that use a small ASA their edge network device.
> Frank
> -----Original Message-----
> From: Dale W. Carder [mailto:dwcarder at]
> Sent: Thursday, March 24, 2011 9:26 AM
> To: Eric Vyncke (evyncke)
> Cc: frnkblk at; ipv6-ops at
> Subject: Re: Setting the "other-config-flag" or O-bit on a Cisco ASA
> Another option you may be able to consider is to run the ASA in transparent
> mode and letting the router route.  This depends on your topology, of
> course.
> Dale
> Thus spake Eric Vyncke (evyncke) (evyncke at on Thu, Mar 24, 2011 at
> 02:52:37PM +0100:
>> Frank,
>> I am afraid that there is currently no way for ASA to set the O-bit (or
> even the M-bit or the router priority)...
>> Next version (end of this year) should have those needed features...
>> Some customers are using a Linux box to send RA with the O-bit
> information, same prefix and low priority
>> -?ric
>>> -----Original Message-----
>>> From: at
> [mailto:ipv6-ops-
>>> at] On Behalf Of Frank Bulk
>>> Sent: jeudi 24 mars 2011 14:39
>>> To: ipv6-ops at
>>> Subject: Setting the "other-config-flag" or O-bit on a Cisco ASA
>>> We have customers that use an ASA and would like to use stateless DHCPv6
> on
>>> their Windows 2008 server to get the DNSv6 servers.  I don't see "ipv6
> nd
>>> other-config-flag" on our ASA nor in the documentation.  How do people
> pull
>>> this off?
>>> Frank

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