Hot answers tagged

10

The route with the longest mask (/24) is always preferred regardless of how it’s learned. The protocol doesn’t matter.


9

The second option is something to avoid. It is acceptable for point-to-point interfaces like serial or tunnel interfaces, but on broadcast media (such as Ethernet), it is "close to illegal" to use (regardless of whether the directly attached subnet is /25, /30 or /31). If configuring the route this way is possible at all (I seem to remember that recent IOS ...


7

Most specific match (longest subnet mask match) will win regardless of routing protocol. If the subnet masks are equal, the route with the lowest administrative distance wins. In this case eBGP routes (learned from routers in different BGP Autonomous Systems) have a lower AD than OSPF routes, which have a lower AD than iBGP routes (learned from routers in ...


7

Can I add a static route Cisco3750Stack#ip route 0.0.0.0 0.0.0.0 10.6.0.1 10 to the existing static route and be able to test connectivity with the new IP scheme No, you can't test in the way you described because your testing static route won't be active until and unless the existing route is disabled or deleted. Basically, a layer 3 device gives high ...


6

TLDR you can't. You can use traceroute to see the path a packet will likely take from your computer to a remote one, however, the very nature of the Internet is that a packet can take any path between two computers, depending on router availability, link failures or congestion, or router specific configuration. Two packets from the same flow could take ...


5

The network mask (or prefix) defines the length of the subnet address in a routing table. Each entry in a routing table consists of subnet address and mask and the next-hop gateway. Each next-hop gateway needs to be locally connected to the router in question, so a network mask is not required.


4

The server's address must be part of the subnet it's configured on. Since you have the server on VLAN 501, its IP address has to be in the 10.50.1.0/24 subnet, not as you have it configured. Set the server's default gateway to the SVI on VLAN 501: 10.50.1.254. Switch 1 also needs the gateway set to the SVI on Sw0: 10.10.10.1, the same way as Sw2.


4

The L route is the local address assigned to the interface, and the C route is the network attached to the interface. That is completely normal (beyond a certain device code version) for interfaces that have smaller masks configured on them. If you configure an interface, e.g. a loopback, with a /32 address, then you will not see a separate L entry for that ...


4

Routers route packets by what is in the routing table, and identical routes will have the one with the best (lowest) AD make it into the routing table, but the other identical routes will not. Then it is checked for the longest match with the routes in the routing table. AD determines what makes it into the routing table, and the logest match in the routing ...


4

If all you're looking for is a way to make sure the new connection can pass traffic, you can add a route for something specific that won't interfere with your normal traffic, such as: ip route 8.8.8.8 255.255.255.255 10.6.0.1 When you're finished, you can simply remove that route and wait until you're ready to replace the default route with the new gateway. ...


3

if multiple route entries are present in router for same destination with different routing protocol means with administrative distance value (AD) value . Lowest the AD value have more priroity to choose route entry Layers 3 devices chooses routing protocols considering AD value (administrative distance) lesser the AD value have more priority for chossen ...


3

NAT happens on a device that can perform NAT, e.g. a router (even layer-3 switches cannot NAT, except for something like the 65xx series). The outside and inside addressing is placed on different interfaces of the NAT device. You will need to either put in a router on each VLAN between the router and hosts, or it may be that your hosts can themselves NAT ...


3

You need to remember that ping is bidirectional. You send out an ICMP echo request, and you hope to get back an ICMP echo reply. That means that the replying device must also have a route back to the original sender. You did not include the R3 routing table, but it would seem that R3 does not have a route back to the source of the ICMP echo request. It is ...


3

The point of that port/VLAN chaining rig is that you want to force the switch to receive and send in port pairs. Normally, a switch would take the shortcut to the (final) destination port which you don't want - you prevent that by placing ports in different VLANs. By using VLAN port pairs, you define single ingress-egress port pairs - each frame that enters ...


3

Personally, I do this type of research using a number of different publicly available "route servers" or "looking glasses." Simply do a web search for "public bgp looking glass" and you should find a significant number of results. Many of these tools now have a web interface you can access, although some are still network devices you can telnet/ssh into to ...


3

All IPv4 networks are subnets of the 0.0.0.0/0 network, so in a routing table that network matches any IPv4 network, making it a default network. If the destination address on a packet does not match any network in a routing table, the router will simply drop the packet. A route pointing to 0.0.0.0/0 matches the network of any destination address. Such an ...


3

From the CLI you can issue the following command to restart the routing service. exec router restart To restart OSPF, you can use. exec router clear ospf process


3

show route <ip address> all shows you all routes received for a given destination, not just the one installed in your FIB. However, if you receive routes from a transit provider, you typically receive only one route to that given destination, being the route via their network. If you are multihomed, show route <ip address> all will show you ...


3

Can I add a static route Cisco3750Stack#ip route 0.0.0.0 0.0.0.0 10.6.0.1 10 to the existing static route and be able to test connectivity with the new IP scheme...? No, you can't. As others have pointed out, since you've set the administrative distance to 10, this route will not be added to the routing table unless the other default route (with lower ...


3

The Juniper documentation here actually words this well. In summary, that is a multipurpose field used to display information about BGP peer sessions. The field’s contents depend upon whether a session is established and whether it was established on the main routing device or in a routing instance. If a peer is not established, it will show the state of the ...


2

The default gateway generally refers to the 0.0.0.0/0 route, which is used when there is no clear routing entry to a destination address As per above sentences ! Default route is configured as when packets wants to reach unknown destination this default route is configured . Generally in real time default route is mostly configured to route internet traffic ...


2

The selected path is chosen because (all else being equal) the local preference (190) is set highest on this path. To change which path BGP selects you will need to modify the local preference.


2

To simplify the explanation, let's just pretend that only RR1 and RR3 exist (and let's forget about RR2 and RR4 for a second). Similarly, let just pretend ASBR1 and ASBR3 are the only ASBRs (and let's forget about ASBR2 and ASBR4 for a second). There is an EBGP session between RR1 and RR3, to exchange the IP VPN routes between the two ASs. That means that ...


2

Suppose, I can buy/ own different PCs/ routers in specific places (GEO locations). Is it sufficient to fully control and determine the packages path? Unless all these routers are directly connected to each other, no. Each hop decides on the egress route on its own volition, its routing table, policies or whatever. You can't influence that on routers that ...


2

What roughly I understand is, advertising route from one vrf table to other. In the context of MPLS, yes. Or, leaking from the global table into one or more VRFs. It is also used in other places, e.g., IS-IS. What type of routes (static, connected, dynamic routes) can be leaked from one vrf to another ? Anything in the routing table. And why do we ...


2

You'll likely want to look into something like Protocol Independent Multicast (PIM), which seems to be covered for that platform here. As Ron points out, IGMP is only managing multicast groups within a subnet. To route multicast between subnets you'll need to enable multicast routing on the platform and then, in most cases, enabling PIM on the appropriate ...


1

All IP Sub-nets connected with a specific Interface should be able able to reach there Next-Hop or Firewall Interface or Gateway First. Can you confirm whether while connecting your system in New Series, you are able to reach your next hop IP that is the IP Of Firewall Interface in this case ?


1

This is a really detailed, illustrated blog post explaining several popular IPv4 lookup algorithms which are used by modern routers and operating systems. In your initial post, you mention sorting; and I believe the method you are considering implies you'd then need to scan the results. You could compare that to scanning a database table to find a string. ...


1

There are different types of traceroute and different ICMP types. In contrast to *NIX traceroute, which uses UDP, Windows tracert uses ICMP. So ICMP echo-request / echo-reply types are allowed (you can ping) but it looks like other types are blocked, this may include time to "live exceed which" is used by traceroute.


1

I assume you want to connect switch interface FastEthernet0/1 to the router interface GigabitEthernet0/1 is that right? If you want to route traffic from vlan 2-11 to the router you must: delete interface Vlan12 configure the IP directly on the interface FastEthernet0/1 interface FastEthernet0/1 ip address 192.168.0.82 255.255.255.248 Now it should be ...


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