Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

Cisco ASA 5505, secondary IP on inside interface, same subnet

Posted on 2014-03-11
6
Medium Priority
?
4,160 Views
Last Modified: 2014-03-19
Greetings,

I have need to have my ASA5505 listen on 2 IP addresses in the same subnet on the INSIDE interface (VLAN1).

The reason - another device with this secondary IP is being removed and I need to have the ASA listen on *both* its own IP and the IP of the device removed, at least until I find every device using the old gateway IP.

Example:
ASA (inside, VLAN1): 192.168.1.1 255.255.255.0

Old device "X":  192.168.1.10 255.255.255.0

I need something similar to (in router-speak):
int vlan 1
  ip address 192.168.1.1 255.255.255.0
  ip address 192.168.1.10 255.255.255.0 secondary
0
Comment
Question by:snowdog_2112
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
6 Comments
 
LVL 29

Expert Comment

by:Jan Springer
ID: 39921978
You need to put the other subnet in its own vlan and dot1q the interface.
0
 

Author Comment

by:snowdog_2112
ID: 39922108
They are in the SAME subnet as mentioned in OP.  Thanks for quick response though.

Both devices have IP's in 192.168.1.0/24.

The old device is gone and won't be replaced, so I need the ASA to "own" 2 IP's on the same subnet - if only for a short while (months, perhaps).
0
 
LVL 31

Expert Comment

by:Gareth Gudger
ID: 39922464
0
Are You Ready for GDPR?

With the GDPR deadline set for May 25, 2018, many organizations are ill-prepared due to uncertainty about the criteria for compliance. According to a recent WatchGuard survey, a staggering 37% of respondents don't even know if their organization needs to comply with GDPR. Do you?

 

Author Comment

by:snowdog_2112
ID: 39924382
Nope.

Again - the secondary IP is on the SAME SUBNET as the primary.  I can't route from one to the other, and even if I wanted to, I can't VLAN it, since both IP's are in the middle of the same /24.

I have a hunch that it is somehow related to NAT - the devices pointing to 192.168.1.10 (the old IP, which has an arp alias on the ASA) are not being NAT'd or unNAT'd properly.
0
 
LVL 12

Accepted Solution

by:
Henk van Achterberg earned 2000 total points
ID: 39935301
The ASA can only have on IP address on the inside interface.

Maybe you can use other solutions like a layer 3 switch or second (cheap) router.
0
 

Author Closing Comment

by:snowdog_2112
ID: 39940750
Love Cisco...

HATE Cisco!

The ASA is "not a router", so for small businesses who might possibly need some routing features, you need an ASA for $500 and another "real router" for another $500-1000.

Or...a $200 Netgear.

At least on an ASA you can type exec commands in conf mode without "do <command>", unlike Cisco routers.

Fair trade-off....maybe.
0

Featured Post

Free Tool: SSL Checker

Scans your site and returns information about your SSL implementation and certificate. Helpful for debugging and validating your SSL configuration.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

During and after that shift to cloud, one area that still poses a struggle for many organizations is what to do with their department file shares.
Let’s face it: one of the reasons your organization chose a SaaS solution (whether Microsoft Dynamics 365, Netsuite or SAP) is that it is subscription-based. The upkeep is done. Or so you think.
As a trusted technology advisor to your customers you are likely getting the daily question of, ‘should I put this in the cloud?’ As customer demands for cloud services increases, companies will see a shift from traditional buying patterns to new…
Both in life and business – not all partnerships are created equal. Spend 30 short minutes with us to learn:   • Key questions to ask when considering a partnership to accelerate your business into the cloud • Pitfalls and mistakes other partners…
Suggested Courses

721 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question