Metalshark's questions

We are moving office and our managed service provider has let us down badly. We have a Cisco 4500 stack with 5 VLANS configured of interest. These are:

interface Vlan200
 description FLOOR0 Gateway
 ip address 172.17.0.1 255.255.252.0
!
interface Vlan201
 description FLOOR1 Gateway
 ip address 172.17.4.1 255.255.252.0
!
interface Vlan202
 description FLOOR2 Gateway
 ip address 172.17.8.1 255.255.252.0
!
interface Vlan203
 description FLOOR3 Gateway
 ip address 172.17.12.1 255.255.252.0
!
interface Vlan204
 description FLOOR4 Gateway
 ip address 172.17.16.1 255.255.252.0

Our old network was 10.0.0.0/8 (inherited it). An example server would be 10.0.0.81. Our entire environment (several thousand devices) cannot be reconfigured to point at our new 172.17.4.81 address as the package deployment for SCCM has just collapsed.

The 10.0.0.0/8 range is not on the 4500's (as it was handled over our MPLS so the MPLS default gateway on the 4500's sent traffic to it anyway).

Is it possible to use static NAT or similar for requests to 10.0.0.81 to point to 172.17.4.81? I became nervy when all examples show applying inside/outside rules to interfaces (I don't have one for 10.0.0.81/8 but could always create a stub VLAN). Also didn't know the consequences of applying it to the VLAN interfaces above (in case I lost access to our production network).

Guessing that adding inside/outside NAT would be harmless but would like to know how you Cisco geniuses would tackle this.

UPDATE:

We've fixed SCCM but for future reference it would still be great to know the best way to handle this.

Does anyone know where EMC host their GNU source code for VNXe products?

We are tired with calling Delhi/Idaho for them to dial in to fix trivial issues and would like to figure out the algorithm of their temporary password system and avoid waiting hours for a WebEx.

Meta

As someone would like to discuss being a professional system administrator it might be worth adding some context. A "solutions provider" mis-sold an EMC VNXe solution to senior management before operations had a chance to intervene. It fails hard in our 24/7 alarm monitoring environment and needs continually fixed.

Every second of downtime when a fire alarm or lone worker alarm comes in increases the chance someone loses their life. It is being replaced, but due to politics between firms and costs this will be a month or two. Meanwhile I don't have time to be messing about with account managers and escalation processes - we need this to work and have access to fix it immediately. Otherwise I'd agree entirely in going through the proper channels.

End of Meta

Is it possible to increase the maximum record size/cache size supported by the DNS server embedded in a Cisco 800 series router (886VA in my case)? I cannot query large (1500b) TXT records without bypassing Cisco's ip dns server.

How do you escape a question mark character in a string on the MySQL CLI?

There are many methods to avoid having to escape characters, but from an ease-of-use perspective I would quite like to do some SELECT statements containing LIKE queries, some of which contain question marks and the usual \? does not work.

NAT options on domestic routers often come configured as strict. What does this mean? What do moderate or open do? Port-forwarding/DMZ access works properly on strict so why bother with the other two?

A look through the router suggests this affects the firewall. When spending a large amount of your time securing networks using Cisco/iptables such a limp non-descriptive answer is nothing but infuriating and leaves no clues as to what effect upon a firewall this has.

Please can someone shed some light.

A simple question (hopefully) but with no clear answers when doing a Google Search. What is the MTU of VDSL (not VDSL2)? With ADSL it was 1492, but most ISPs added PPPoE/PPPoA headers reducing it to 1452, is this still the same when it comes to other types of DSL (including VDSL)?

We have 8x IP CCTV Cameras and 1x NAS for recording on a LAN (with an internal address range) and port forwarding from a single WAN address to connect to each. For instance, by connecting to port 8009 on the WAN IP we can access the NAS, connecting to port 8008 on the WAN IP connects to camera 8, etc.

The software for connecting to the CCTV cameras and NAS only allows one IP address to be entered (the external one). We used to only access the cameras/NAS whilst external from the building, so this worked fine. However now we may be on the LAN itself, and the Cisco Router/Firewall isn't performing the port forwarding magic we need (it drops the packets).

How do you get a Cisco Router/Firewall to honour WAN IP + Port Forwarding whether you are on the LAN or external?

Having spent some time on a rack mounted server yesterday afternoon we are now trying to determine the most probable cause of two DDR2 modules failing on an IBM server simultaneously.

The server would boot with either both modules, and with one at a time, but failed at the 12% mark on MEMTEST86+.

Some replacement memory is working perfectly, it just seems odd that both sticks would fail at the same time and have the exact same problem in a certain area of memory.

Does anyone know what would cause this?

If its a known issue with some vendors this is a relatively new IBM rack server.

On a Linux Apache server, from time to time, there are messages saying TCP: Treason uncloaked!.

There are previous questions on ServerFault explaining the fixes for this issue.

However does anyone know the meaning of this error message? Why would mis-matched TCP messages provoke such an unclear error message? Has this message got some history behind it?