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Q: How do I prevent the Code Red Worm from crashing my HP ProCurve Switch 212m and 224m?
The Code Red Worm tries to attack devices using tcp port 80. The HP ProCurve Switch 212m and 224m use port 80 for establishing http sessions. If your HP ProCurve Switch 212m or 224m is running software version D.05.13 or earlier, when the Code Red Worm attempts to attack the switch on tcp port 80, the switch will crash with a message similar to:
Exception, # = 2 IP=0x000a4c3e SR =0x00003000 FCode= c
Task='mHttpCtrl' Task ID=0x307dc0
The switch will then reboot automatically. Network operations will be momentarily interrupted during the reboot.
If your switch is running software version D.05.14 or greater, it is not affected by attacks from the Code Red Worm. If your switch is running an earlier version of software, you should upgrade to version D.05.14 or greater.
If you do not want to upgrade to software version D.05.14 or greater, the workaround for the Code Red Worm issue on the HP ProCurve Switch 212m and 224m is to disable the Web Agent on the switch. Follow the steps below to disable the Web Agent:
- Establish a console session to the HP ProCurve Switch 212m or 224m.
- From the Main Menu select "2. Switch Management Access Configuration (IP, SNMP, Console)...".
- From the Switch Management Access Configuration Menu select "4. Console/Serial Link Configuration".
- From the Switch Management Access Configuration - Console/Serial Link screen set the "Web Agent Enabled" parameter to "No".
If you have more than one HP ProCurve Switch 212m or 224m, the above steps must be repeated for each switch.
While other ProCurve Networking by HP switches also use tcp port 80 for http sessions, only the HP ProCurve Switch 212m and 224m are affected by attempted attacks from the Code Red Worm. Note, however, that you might see a message logged on other ProCurve Networking by HP switches similar to:
TCP: port 80 to port pppp at xxx.xxx.xxx.xxx timed out
where "pppp" is the tcp source port number and "xxx.xxx.xxx.xxx"
is the IP address of a system affected by the Code Red Worm.
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Q: When I power on my PC, I get the message "a file server could not be found." How do I fix that?
This is a well-known issue given the following situation:
- The PC is directly-connected to a switch
- The PC is running Novell's VLMs or Client32
- The switch has Spanning Tree Protocol (STP) enabled
In this situation, when the directly-connected PC is powered on, the switch senses linkbeat on that port. This causes the switch to go through the four Spanning Tree states: blocking, listening, learning, and forwarding. It takes 30 seconds for the switch to complete that sequence and begin forwarding packets to and from that port. During those 30 seconds, Novell sends 3 requests for a server, then stops looking. By the time Spanning Tree completes its job, Novell reports that "a file server could not be found".
There are several workarounds available:
- Disable Spanning Tree on the switch (if Spanning Tree is not needed, i.e. no loops in the network topology).
- For VLMs, add a "pause" just after calling VLM.EXE in STARTNET.BAT. When the user reboots a PC, have them wait at least 30 seconds before continuing the sequence. This workaround is documented on Novell's Knowledgebase (www.support.novell.com, search for document 2920460).
- For Client32, add a registry entry in the PC, as documented on Novell's Knowledgebase (search for document 2925582).
In the Fall of 1998, HP released switch firmware with an enhancement to resolve this timing problem between Novell and STP. The enhancement allows users to configure Spanning Tree so that it does not go through the 4 states, on a port-by-port basis. Instead, for those configured ports, Spanning Tree will immediately begin forwarding packets to and from the port. This allows Novell clients to communicate with the server as soon as the network card (NIC) is enabled. After that, the switch continues to listen for and send Spanning Tree packets on those configured ports. This protects the user who might inadvertently connect a hub or switch to that port and create a network loop—Spanning Tree will detect the loop after a short time, since the port listens for and sends STP packets on that port.
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Q: Do the HP ProCurve Switch 212m and 224m support IGMP (Internet Group Multicast Protocol)?
Yes. These switches do implement IGMP and therefore are able to control distribution of multicast packet streams based on which ports have subscribers to particular multicast groups.
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Q: Do the HP ProCurve Switch 212m and 224m support 802.1p priority?
No. These switches do not implement the 802.1P priority standard. However, there is a configurable option that allows the switch to send IGMP packets with high priority over normal traffic. This feature is located on the IGMP Service configuration screen under the Advanced Features menu of the switch console interface.
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Q: Do the HP ProCurve Switch 212m and 224m support 802.3 Tagging VLANs?
These switches are compatible with the larger (1522 byte) tagged packets created when VLAN tagging is implemented on a network. However, VLANS are not configurable on these switches. So these switches will pass the 1522 byte tagged packets but will not read and act on the VLAN ID which is contained in the tagged packets. This means that these switches can be used on networks with tagged packets but the tagged packets will be treated as normal packets and switched to proper ports.
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Q: Is 10/100Mbps auto-negotiation the same as Plug-n-Play?
No. The following configuration will cause severe network problems:
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The hub, switch, or router will correctly sense (not auto-negotiate) the 10Mbps or 100Mbps speed. Since the end node was configured for a specific speed and duplex state, and therefore does not negotiate, the hub, switch, or router will choose the communication mode specified by the 802.3u standard, namely half-duplex.
With one device running at half-duplex and the device on the other end of the connection at full-duplex, the connection will work reasonably well at low levels of traffic. At high levels of traffic the full-duplex device (end node, in this case) will experience an abnormally high level of CRC or alignment errors. The end users usually describe this situation as, "Performance seems to be approximately 1Mbps!". Often, end nodes will drop connections to their servers.
In this same situation, the half-duplex device will experience an abnormally high level of late collisions.
The network administrator must take care to verify the configuration of each network device during installation. Also, check the operational mode of each network device. That is, check both how you configured it and also that it comes up as you expect, for example, at 10Mbps/half-duplex.
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Q: Why won't my iMac, which is directly attached to an ProCurve Networking by HP switch, NetBoot from an OS X Server, even though it worked correctly when my iMac was plugged directly into a hub?
This issue is not specific to HP switches. Rather, it is a timing problem in early versions of the iMac Boot ROM. Apple Computer, Inc has fixed this NetBoot issue by releasing both an updated Boot ROM image and Mac OS X Server version 1.2. Please advise customers with iMac NetBoot issues to contact Apple Computer, Inc Technical Support.
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Q: Why is my Macintosh system unable to use AppleTalk services?
Possible symptoms include: no AppleTalk services, only local network AppleTalk services, performance problems, and intermittent network services. If you remove the Macintosh from its dedicated switch (or routing switch or router) port and connect it to a hub, the problem goes away.
If the switch (or routing switch or router) has Spanning Tree Protocol enabled, see Apple Computer, Inc's Tech Info Library entry "Spanning Tree Protocol: AppleTalk and NetInfo Issues".
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