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Questions tagged [ip-forwarding-table]

For questions involving the IPv4 or IPv6 Forwarding Information Base (FIB).

2
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1answer
35 views

Two channels between two switches

Is there a way to provide two physically diverse channels between two switches? I'm using two Cisco Catalysis 3560s, and I want to have two separate channels between them, with different access ...
0
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1answer
32 views

Reach IP in Parent Network

We have a router (Router 2) inside a network (Router 1) with a client (Client in Router 2) that needs to make a TCP connection to a client in router 1. We only have access to configure Router 2 and ...
5
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3answers
954 views

What is the different between routing table and forwarding table?

What is the different between a routing table and a forwarding table?
0
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1answer
49 views

Sys Routing Table Router: Destination IP, Gateway IP and Public IP are different, something unusual? [closed]

I am currently studying my home network router Sys Routing Table and attempting to resolve WHY my Public IP (assigned by my ISP), Gateway IP (WAN) and Destination Network (WAN) are all different. I ...
1
vote
1answer
95 views

Deploying Dijkstra's Algorithm in a Fat Tree Topology!

I am trying to deploy Dijkstra's Algorithm for finding the shortest path between switches in a balanced fat-tree topology. The problem is that I do not know what values/unit of weight should be in ...
4
votes
1answer
239 views

Switch FIB and router FIB

Forwarding Information Base (FIB) also called Forwarding Table or Mac Table according to wikipedia. I first explain my understanding of the FIB in both Switch and Router. Does not hesitate to correct ...
1
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1answer
191 views

Why is Next-hop address the same with Interface address in forwarding table?

I read about TCP/IP Illustrated, Volume 1: The Protocols (2nd Edition) 5.4.3.1 Direct Delivery, this chapter illustrate the direct delivery like below: But what confuse me is the forwarding table of S:...
1
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2answers
928 views

Forwarding tables in hosts [closed]

I'm an engineering student studying networking from Kurose's A Top Down Approach. I got stuck on an exercise from chapter 5 (link layer) and wanted to fill in the gaps in my knowledge. The exercise ...
2
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3answers
957 views

Forwarding to multiple output ports using SDN

Using switches that support OpenFlow, is it possible to forward packets for specific flows to multiple outgoing ports, so that each port receives a copy of the packet (similar to multicasting scenario,...
1
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1answer
329 views

Flat vs Hierarchical FIB

I've been reading about FIB and tried to understand the design, I read that FIB and RIB have one-to-one correlation. 1.What does it mean they have one-to-one correlation? 2.In my understanding - ...
0
votes
1answer
344 views

Ping issue: connect a switch into another switch's vlan port

I have a Cisco 2960-X switch and a Cisco SG-300 switch. I created VLANs on 2960-X switch (e.g. VLAN 10 with ports 1-5 and VLAN 20 with ports 6-10) and allow DHCP for each VLAN. Now, laptop 10.10.1.2 ...
0
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1answer
1k views

Port forwarding and dynamic IP address [closed]

I have a basic confusion about how port forwarding works with DHCP assigned IP addresses. If I set up port forwarding on a raspberry pi using its internal IP address and then set up dyndns so that ...
1
vote
1answer
37 views

Which sources of information are used to forward packets?

I am trying to better understand how routing works in practice. Which sources of information (can) go into the forwarding decision that a router makes? I have learned that BGP Updates from ...
0
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2answers
429 views

Determining next hop adress in packet forwarding by forwarding table (IPv4)

Say that we have a router with the follwing forwarding table -------------------------------------------------- | Destination | Next hop | Flags | -------------------------------------...
2
votes
1answer
52 views

The meaning of routing table lookup at a line rate

When it is said: Routing table lookup in a line rate, why is line rate important when the router still needs to perform a linear search in the size of routing table? Is there a relationship between ...
1
vote
2answers
70 views

Does a router that connects to multiple networks, has a network card and forwarding table for each connection?

Say we have a router that connects to other routers and they connect to lan networks, does that router have a network card for each router it connects with but a single forwarding table for all? or ...
0
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1answer
56 views

Switch: Misbehaving Client

Consider a switch with an empty forwarding table. Connected clients are * A (Port 1) * B (Port 2) * C (Port 3) A wants to send a package P to C. When the switch receives this package, the switch ...
2
votes
2answers
280 views

Is Longest Prefix Matching(LPM) Done in Data or Control Plane?

I have a strong confusion on this whether LPM is done in Data or Control Plane. My thoughts on this is as follows if its in data plane, we will have to do it for every packet hence we will have a ...
2
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2answers
1k views

Cisco 2851 Static NAT - Similar Static Entry Already Exists

I have a Cisco 2851 with NAT configured as so: ip nat inside source list 111 interface GigabitEthernet0/1 overload ip nat inside source static 192.168.16.16 64.xxx.xxx.233 ip nat inside source static ...
1
vote
1answer
73 views

Which fields in the IPv6 header are checked during an IP lookup?

I'll consider IPv6 headers for this question. I assume that the simplest IP lookup scheme implementation would just look at the 'Destination Address' field in the IP header of an incoming IP packet. ...
3
votes
2answers
645 views

OSPF, BGP & Forwarding tables

I'm little bit confusing about the flow of things that happen during a voyage of packet in the internet. my basic question is : What is the connection between OSPF and forwarding tables? Suppose ...
0
votes
3answers
363 views

STP, Distance vectors, LS and ECMP confusing

I currently taking a computer networking course and there are some terms that really confusing me and i can't find the "connection" between them. Suppose I have a network with hosts and routers, ...
1
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0answers
393 views

vMX L3 MPLS VPN routes not in forwarding table

I'm new to juniper technology and I'm trying to set up mpls vpn on vMX. Not sure if I'm missing something in configuration or if this is some kind of bug in vMX or if this is not supported on vMX. As ...
1
vote
1answer
1k views

Basic example of forwarding tables

This is my network. The forwarding tables I provide them bellow. I am able to establish the connection between Office1 and R1 but I am not able to connect with R2, as for a reason I do not know, all ...
3
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1answer
756 views

Routing and Forwarding Decisions

We need to build a routing table, based on routes from neighbors.. Route A receives three routes from different Routing Process: EIGRP - 192.168.100.0/26 OSPF - 192.168.100.0/19 RIP - 192.168.100....
0
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2answers
569 views

Ip forwarding & routing table advanced example! [closed]

I'm have a big question regarding IP forwarding. The current situation is like this: I want to send a packet from the client to the server, between them I have two routers, Router1 and Router 2. ...
1
vote
1answer
68 views

Pair two communicating processes separated by two firewalls

Suppose you have 4 processes inside one network (no firewalls) and you see (hostnames A,B,C,D): From A:1 -> C:3 From B:2 -> D:4 Therefore you know A is communicating with C and B with D. Now ...
0
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1answer
8k views

Why cant i NAT to a local network address on my UBNT edgerouter

I am trying to set up a very simple network. I have an Ubiquiti Edgerouter on 192.168.1.1 with eth0 as WAN port. I also have an Ubiquiti Rocket m5 on 192.168.1.2, both the router and the Rocket have ...
0
votes
1answer
4k views

Configure DNS Table on Sonic Wall TZ205

I just installed a TZ-205 on our company network and I can not seem to find where I would add to a DNS table. On our Linksys LRT224 there is a option to add a domain name and an associated IP. Does ...
4
votes
2answers
447 views

coexistance for the longest prefix match

For example, can 128.92.128.0/17 and 128.92.128.0/18 be contained in one forwarding table together? Or the first one must be changed to 128.92.192.0/18? Because the other half will go to the second ...