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Posts published in “Computer & Internet”

Mitigating a IPv6 malformed packet multicast flood

So we just had our first IPv6 multicast flood in the network this morning.
We managed to stop the offending computer by blocking the mac address with:
mac-address-table static x.x.x vlan x drop

Before we blocked the mac addr...

TCP/IP Header compression

I'm reading RFC 1144 and I'm trying to figure out how the TCP/IP header compression works. As I understand it, the sender only sends a couple of fields that are likely to be changed.

If the packet doesn't contain the IP of t...

What is the advantage of an “area” in OSPF configuration?

As we know, during OSPF configuration we use the area. Each area has its different number, while there is only one area (area 0) which creates communications between all other attached areas.

I am confused that as we are u...

Nexus 5020 default route

I just setup a nexus 5020 and while I know it's primary purpose is to be used as an L2 device, according to docs, I should still be able to set a default route in the global routing table. However, it does not seem to be wor...

Zyxel USG100. GS1910 Vlans cannot access wan

Iam trying to configure a network that looks like this:

My Vlans and static routing seams to work fine, i am able to ping between the VLANs. My problem is, when i try to make a connection to the internet, I get a time out ...

Routing of 2 Gateways via a Layer 2 Switch

Please refer to the network diagram below, it is a very simplified version of an actual network installation.

The Router has 3 Vlans, OSPF has been configured and all the 3 vlans have been added to Area 0 so they can communi...

Block ICMP ping from a PC to a PC

I have a topology like this

PC1 ------Switch
PC2 ------Layer --------- Router

PC1 VLAN 10.

PC2 VLAN 20.
PC3 VLAN 20.

I configured a router on a stick to ping between ...