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RV320 Class A Subnet Support

chrisbennettga
Level 1
Level 1

We have a RV320 that is the core of our church network. We initally purchased it to serve 3 primary networks: the office network (closed), the general purpose network (also closed but not on the office network) and a guest network.

The router serves the first two scenarios well, but the third is a problem in that we need to be able to deliver >253 IP addresses for gues access. The RV320 doesn't seem to support any better than /24 subnetting, so I am wondering if anyone has found a workaround.

I would love to NOT have to rely on the consumer class WAP we are using to serve guests at the moment, and leverage the all Cisco gear we purchased for the network.

It seems odd to me that a $50 Linksys / Netgear / TrendNet router can leverage a Class A subnet and deliver up to 750 IP addresses via DHCP on a single subnet but this Cisco product cannot.

Thanks in advance...

19 Replies 19

SamirD
Level 5
Level 5

If this is serving everything but the guest network fine, why not just get a consumer level access point router and be done with it?  Trying to get everything running on the rv320 may cause other issues.  Since it is guest access anyways, it wouldn't be critical, would it?

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Mainly because we also have a pair of Cisco WAP550 clustered AP's. These provide excellent coverage, and we would prefer to use them.

We can run DHCP outside of the RV320 - but the problem remains that in order to use the WAP550's we would need to define the VLAN on the RV320. Since the RV320 doesn't allow anything but a class C subnet, we can't do that. We need a class A subnet in order to  deliver >253 IP addresses.

It's a really silly problem to have - especially in a Cisco product.

same problem here.

we want to configure inter vlan routing with an existing class B subnet and a new with a class C subnet. but we are not able to do this because of the class C restrictions of the RV320.

if this feature was enabled, the cisco RV320 would be a very complete product.

i'm sure the RV320's hardware can handle class B subnet without any problems. this is pure software limitation.

I suppose I should have posted an update. After spending several thousand $US, we have given up on Cisco. The Wireless Access points, VPN routers and switches ALL proved to be completely unreliable or missing basic functionality. We sold the entire lot on eBay for a fraction of what we paid, and won't be looking to Cisco again.

Not sure if this will be moderated out, but we looked to Ubiquiti Networks and have been very pleased with the scalability and performance of their router and wireless products. And we've spent less than half of our Cisco investment to install the new solution.

SamirD
Level 5
Level 5

Ahh, this makes more sense now.  Have you tried using the 10.0.0.0/8 private network?  This is actually a class A that's reserved for private use.  You could also use 172.16.0.0/12 as it's class B, but still has enough addresses.  I actually thought the newer RVs could do more than 254 IPs by allowing at least class Bs?

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That's the issue. The router doesn't allow the definition of a VLAN with anything but a /24 or /24 based VLSM (/25, /26, etc). There is no way to configure a /8 or /12 subnet mask.

If I use a $50 TrendNet router, I can create a 10.1.1.0/8 network and create a DHCP scope of 10.1.1.2 - 10.1.2.254 which allows for 507 IP addresses. No need for multiple DHCP servers.

Cisco needs to fix this issue. It's a serious shortcoming. Absent that, we'll have to replace the router. It's a very _BASIC_ flaw. It would be awesome if someone from Cisco would chime in and let us know if (1) they're looking at it or (2) it is what it is - and won't be fixed. I did call the TAC and they said it was a "feature enhancement" not a bug and that I should post the question here.

Pretty dissapointed in Cisco to be honest...

This is probably keeping in line with 'good' IT infrastructure.  Check out this thread I found for a couple of solutions to your issue:

http://community.spiceworks.com/topic/220802-running-out-of-dhcp-ip-addresses

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SamirD
Level 5
Level 5

I thought a little more about your problem, and it's actually not an issue with the class of IPs, but that you need multiple DHCP servers since each only does 254 IPs.

I don't know if you're going to find an SMB router that can handle that.

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chrisbennettga
Level 1
Level 1

At issue here isn't that I am running out of DHCP addresses. The real issue here is the inflexibility of the RV320 router. The RV320 will not allow ANY subnet mask for any network that is bigger than a /24.

Even if I were to utilize an external DHCP server, I could not create a VLAN on the RV320 that would support >253 IP addresses - because the largest network I can create on the RV320 (by subnet mask) is 24 bits. So, I am stuck either leveraging an external WLAN and ignoring the investment I've made in Cisco platforms - or I "throw away" the RV320 and leverage someone else's router that doesn't have such a ridiculous limitation.

Still waiting for someone from Cisco to weigh in on this.

Interesting.  This was a limitation earlier on with the v1 rv016, then they lifted the limit in v2, and then seem to have brought it back for the newer rv series.

I think you're beating your head against a brick wall about Cisco changing it in time for your project.  Unless someone knows a workaround, I think you only have a choice of changing the router or keeping it with the limitation.

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Hi Chris, this inflexibility has been present for years on the small business products. These products were initially designed with less than 100 user networks in mind and are designed as such. Although it is quite arguable they may support more, they're not designed for more.

If you actually plan on using 250 IP addresses, this probably is not the best product for you.

-Tom
Please mark answered for helpful posts

-Tom Please mark answered for helpful posts http://blogs.cisco.com/smallbusiness/

Hi Tom Watts,

I have to correct you as your statement does not match the basic maths of today's network. I would say that it was designed for less then 64 users in mind. As a lot of business provide lots of devices to there employees. Considering that a user can have up to 4 devices (Workstation, Mobile, Laptop, Tablet), then 254 IP / 4 Devices = 64 users. Thus the product was poorly designed from the get co. And should of at least support Class B Addresses if it where to support up to 100 users.

 

Regards

rnetsystems
Level 1
Level 1

this is not the case of "small business routers", there is many "small business" routers which will allow you to customize subnet and they are way less powerful than RV320 - in my opinion it is shortcoming off the software design.

Here is a proof:

RV220W small business router also from CISCO (very similar spec - it has wireless instead of dual WAN) - it will allow you to create any subnet. Do not blame "small business" routers. As you can see Cisco can give you any class subnet for RV220W but RV320 which suppose to be the same -  they created a limit - I do not know why and I will call them tomorrow. Just got RV320 and I am pleased with all but subnet issue.

OK - what if you have existing network  with subnet 255.255.0.0 and about 100 nodes ? Should I rip off all network settings from servers, DNS servers, workstations, DVRs, printers etc to accommodate RV320 ? I really would like to use and promote RV320 for my clients due to its performance but with current subnet issue I am not able to.

RV320 is GREAT router, AWESOME specs - but Cisco needs to fix subnet issue. I will call them and ask for solution. I have RV220W but need solution for my clients for dual WAN and  WAN fail over.

If the 220 does the job, then that may be the main difference between it and the 320.  I always wondered why there's such a mix of products that have dual wan capability, and maybe this is one of the differences.

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