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0

If you're using the EPEL packages, most of the plugins are split into separate packages so the check_snmp plugin is in the nagios-plugins-snmp package.


1

A Cisco router will not let you have interfaces with overlapping IP address ranges (unless you start looking into VRF's). R1(config)#int fa0/0 R1(config-if)#ip address 10.10.1.2 255.255.255.240 R1(config-if)#int fa0/1 R1(config-if)#ip address 10.10.1.3 255.255.255.240 % 10.10.1.0 overlaps with FastEthernet0/0 To be honest, the topology that you propose ...


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I have been pulling my hair out with this same problem as well. I think I finally found the solution and decided to post it in case anyone else is searching the web for it. Go to Administration -> Management Interface -> IPv4 Interface Under "Administrative Default Gateway" change the radio dial to "User Defined" and manually enter the IP Address of ...


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See https://wiki.wireshark.org/Ethernet and https://wiki.wireshark.org/VLAN If the type/length field is: 0 - 1500: length field (IEEE 802.3 and/or 802.2) 0x0800: IP(v4), Internet Protocol version 4 0x0806: ARP, Address Resolution Protocol 0x8100: IEEE 802.1Q frame 0x86dd: IPv6, Internet Protocol version 6 So if the type/length field is 0x8100 then the ...


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How do I accurately predict the size of IPv4 packets with vLAN tags from reading the header? IPv4 packets do not have VLAN tags in the header. Only the ethernet frame (layer-2) header will have VLAN tags. An IPv4 packet (layer-3) is the payload of the frame, and the IPv4 packet header will not know anything about what is in the frame header. These are ...


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Note that the M-eth0 interface referred to in the documentation appears only when the switch boots to "emergency shell" mode. This happens when the switch can't find a usable system file. The documentation is not wrong as this is always mentioned in the "Emergency shell commands" section. But there is a lack of information about the other M-...


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You can't have two untagged VLANs on a single switch port, and wouldn't want to do that regardless. You'll likely need two NICs in your machine, one on each VLAN, if you can't route between the VLANs. If your OS supports VLAN tagging and treating that as a separate interface, you could have one untagged and one tagged VLAN configured to do that on a single ...


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Balance-tlb (mode 5) and balance-alb (mode 6) do not work with virtual bridges. They can cause broadcast loops, they rewrite source MAC in packets under some conditions, and mode 6 intercepts ARP by design. You need to use active-backup (mode 1) with no switch config, or balance-xor (mode 2) or 802.3ad (mode 4) with switch config. You could also use round-...


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https://en.wikipedia.org/wiki/Unicast_flood It is possible that your :::::::""""hosts with ARP timers longer than the address cache timeout on switches.....""""" as per the article. Try setting your KVM hypervisor host's and VM hosts', ARP timers to be shorter than that of the Switch itself, to which they connect through the physical ethernet port. ...


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That is correct. With no Vlans, and therefore no network segmentation, ARP spoofing is particularly problematic because all clients are affected regardless of subnet. For example, if you have a client on say 172.21.1.100/24, a gateway on 172.21.1.1/24 and a malicious actor on 192.168.1.100, gratuitous ARP messages can be sent to all devices, pertaining to ...


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Assuming you are talking about Link Aggregation Groups (please specify, because "LAG" can have many meanings), they only make sense when connecting two switches together, or two network ports on the same server, or in any other situation when you want to treat two physical links as a single logical one (this is known as "Etherchannel" in Cisco land). This ...


1

You're using /24 on one switch and /28 on the other. That means 192.168.0.1 thinks 192.168.0.17 is in the same subnet, it is not. You'll need to route between the networks.


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So I ended up using an Etherchannel (ports 23/24 on each switch). I setup VTP. I setup HSRP for fail over routing. This was the key, as with trunks (dot1q). I have my servers running SFT between switches. This way, if one switch fails, I have routing, trunking, and core layer 2/3 capabilities. While it's not VSS, it's getting much of what I need done. One ...



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