MAC or IP information may not be learned by the NetWatch tool if there is a user firewall device between our gear and yours. If your department runs its own router for IP hosts in that VLAN, you should be able to take that MAC address, and log in on your router for that LAN, and look in its ARP cache to see what IP address it says it's using. XXI engineers can look for mis-configured ports this by using CodePusher to run "show mac-address-table dynamic" on all devices matching "^-", then examining the logs afterward to find any non-uplink port that has learned that MAC. Mac address-table notification change history-size 500 Mac address-table notification change interval 300 Snmp trap mac-notification change removedĪdditionally, the following lines should be configured on the device itself: The following lines are needed in the config to generate MAC address traps (which our system subsequently learns): If that doesn't yield anything, try a wider time range, like 9999 days rather than past 5 days (which is the default).Īnother reason that MAC addresses aren't learned is that the switch port is incorrectly configured. This causes NetWatch to show where the MAC address was seen, even if it doesn't know what IP address it was using. Try the query again, but this time click "with unknown IP addresses". If no results are returned it means that the MAC was not found using the given selection criteria. Q: Does the NetWatch database have information from csscplat devices?Ī: There are many reasons this might be the case: Q: What's with the weird addresses in the NetWatch database? Q: Why do I get a 'Target Unknown' error when I click on 'Bits', 'Pkts' or 'Errs' for a particular port? Q: Why is my MAC address displayed with '127.0.0.1' as the IP address? Q: Is it possible to query all managed switch ports that have multiple mac addresses on them? Q: Is there a way I may find which enabled ports have been "inactive for N days" on a switch? How can I confirm what's really going on? Q: I think some information in the NetWatch database is outdated.
QUERY SWITCH FOR MAC TABLE SNMP UPDATE
Q: Is there a way to force NetWatch to update its view of the world? Q: When I input an IP I see several MAC addresses, but when I enter one of those MAC addresses I only get one IP. Q: I've tried querying NetWatch for IP addresses I know are connected, but no results are returned.
Q: Why are multiple rows returned for a single device port? Q: I've entered a MAC address in the NetWatch page, but the results seem out of date. Q: I've entered a MAC address in the NetWatch page, but the only result I get is a blank page. Q: How do I do a query on a specific MAC address? If this is the case, you can find the MAC address on the gateway router then use NetWatch to search by MAC address to find the switchport(s) on which that MAC has been seen, if it has been seen on DoIT-managed switches. This would be the case, for instance, if you are a "delegated" customer. Users will not be able to use NetWatch to find information on IP addresses that are not routed on the XXI campus network routers. NetWatch only knows the IP to MAC relationships that it learns from the DoIT-managed routers that it monitors. If IP or MAC addresses show in the NetWatch report, then we reliably know they have been on the network at least at the dates shown when you click "with dates", but it does not necessarily mean that they haven't been on the network if they weren't learned. However, this has been slowing as more switches have been added to the new campus network. "cd /var/local/watch/physaddrwatch & make -s ngrun" die "exec: $!"' The physaddrwatch tool is run four times an hour by cron:Ġ,15,30,45 * * * * /usr/bin/perl -e '$_ = (getpwnam($ENV "-". However, if a machine is continually producing traffic, then the switch will not relearn the address (since it already knows that that MAC is on the given port) so, AANTS will only periodically re-discover that address. So, when you plug a machine onto a port, and that machine then generates an ethernet frame, AANTS (and EdgeConf forms which display it) should show that new value immediately. NetWatch's notion of the current MAC address in use on a given port, is updated in two ways:Ģ) Whenever the MAC address is learnt, the switch is configured to send it to our service (as an SNMP trap). The NetWatch database tables record the MAC addresses seen on a given port, and the IP-to-MAC relationship observed (at a different point in time) as learned from the router ARP tables. The tool tries to show the IP address that was most recently seen associated with a given MAC address.
The AANTS NetWatch tool displays MAC address and IP information for device ports on the XXI network. This document attempts to demystify the AANTS NetWatch tool.
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