Questions tagged [routing]

For questions about routing, the process of selecting to which network path traffic is sent. Consider using a more specific tag if your question is about a routing protocol like BGP or OSPF.

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48 views

Can you tell whether a device is a gateway or not from its routing table?

When looking at a device's routing table, can you tell whether it is a gateway device between some networks or if it is not a gateway device?
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2answers
97 views

Finding a lost device

I have a device - an old printer I think - that is showing up in my traffic flows. It is from a decommissioned subnet (100.100.100.0/24). It is passing one of my network taps and triggering alerts. ...
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1answer
43 views

Is “gateway” a concept between two or more networks or a concept belonging to just one network?

Is "gateway" a concept between two or more networks or a concept belonging to just one network? When a device is connected to two networks, if it is listed as gateway in the routing tables of the ...
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3answers
168 views

Do all network devices need to make routing decisions, regardless of communication across networks or within a network?

From Hunt's TCP/IP Network Adminstration: Gateways route data between networks, but all network devices, hosts as well as gateways, must make routing decisions. Is it correct that routing ...
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4answers
82 views

Does a gateway need to be designated?

Does a gateway need to be designated? I thought a gateway between two networks is a device explicitly designated to be a gateway, out of several qualified devices connected to both networks. That ...
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1answer
69 views

Unable to Ping Past Firewall

I am trying to get communication across a firewall, but I am unable to ping anything past the firewall. PC1:172.16.201.22 <-> Router:172.16.192.1 <-> Firewall_Port1:10.10.10.4 <-> ...
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1answer
170 views

Advertise all static route except the default gateway with Juniper SRX firewall

With the following policy, all static routes are advertised via BGP to my neighbor: root@Nitrogen# show policy-options policy-statement bgp-export-policy { term export-statics { from ...
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3answers
155 views

Inter-VLAN Routing Issue

As you can see in below diagram regarding the Inter-VLAN between Server (VLAN 107) with The site in (VLAN 104)actually, we can ping all the inter-VLAN on the site. but we cannot browse some of them ...
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1answer
26 views

Can a hub be used for sniffing traffic from a device?

My intention is to analyze all network traffic which is coming to and originating from a network connected device I have. From the configurations of the device I am able to proxy all the HTTP traffic ...
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1answer
344 views

What does routing an IP address mean?

From https://stackoverflow.com/a/40189197/156458 Blocking 0.0.0.0 makes no sense. In IPv4 it is never routed. What does "routing" a IP address mean? Why is it the reason that blocking 0.0.0.0 ...
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2answers
83 views

Is static routing used in large networks?

I'm a beginner in networking stuff and just wondered if Static Routing has any use in large networks ? How about small ones ? In which cases we prefer to use static over dynamic routing ? I searched ...
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1answer
32 views

EIGRP unequal load balancing, variance command

Is correct to say that the value inserted in the variance command, lets say the value of "2" on a route that has a cost of, lets say "100", will unequally load balance all routes up to a cost of 200 ? ...
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1answer
82 views

EIGRP Auto-summary

One more question about EIGRP, EIGRP auto-summary what is the impact on the network ? i was reading about but it was not clear for me. And why is it a good Cisco practice to be disabled ? I am ...
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1answer
40 views

EIGRP metric claculation

I have a question regarding the EIGRP metric system. so if K1 is the Bandwidth and formula is : (K1 * BW + ((K2 * BW) / (256 - LOAD)) + K3 * DELAY ) * (K5 / (RELIABILITY + K4) Whats is BW and ...
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1answer
36 views

Packet tracer - why “show ip route” shows network address

This is just a quick question I am wondering out of curiosity. When I set up a network in packet tracer, why does "show IP route" show the network address (example: 199.120.5.64/27) and not the IP ...
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0answers
45 views

Colocation network setup - 2 switches with each 1 uplink - redundant configuration question

I have a question about the network configuration when connecting 2 switches in a colocation rack via 2 uplinks (1 uplink to each switch) to 2 other switches of the datacenter itself. My topology ...
6
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1answer
283 views

Can non-recursive BGP route be used to determine next-hop for recursive BGP route?

In BGP recursive scenario, the recursive route is taking an unexpected next-hop. Here is the routing table: S* 0.0.0.0/0 [10/0] via 10.10.10.1, wan B 172.16.5.0/24 [20/0] via 172.80.80.1, MPLS, ...
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1answer
73 views

Allowing only routed traffic, block intra-VLAN forwarding

In a mixed network of Dell and HP/Aruba devices, we would like to block all communication between client computers, and only allow them to communicate with servers located on a different VLAN*. There ...
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1answer
37 views

What are the differences between packet forwarding and network address translation in layer 3?

What are the differences between packet forwarding and network address translation in layer 3? Is packet forwarding done by a router between two networks that use public IP addresses? Is network ...
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2answers
72 views

Do the Master/Slave Election happen in Broadcast Domain in OSPF? if not Why?

According to my knowledge, Mater-Slave election is needed to decide who will to start communication between two routers. In broadcast domains all the DR other routers communicate with DR. Is there a ...
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0answers
40 views

IS-IS Interface Metric/Cost Calculation Issue in Juniper MX

I am facing a very strange issue with regard to IS-IS Interface Metric / Cost calculation in Juniper MX. We have configured a reference bandwidth of 1000G on all routers.This by definition means an ae ...
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1answer
63 views

Understanding OSPF

In OSPF, what happens first, the SPF tree or the SPF algorithm? Once the LSDB is created does the SPF tree get created first and then the SPF algorithm runs or does the SPF algorithm run and the SPF ...
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1answer
57 views

Cisco ASA not passing traffic between two interface

I have Cisco 5506 with Security Plue License and following is my configuration. interface GigabitEthernet1/1 nameif inside security-level 100 ip address 10.0.10.1 255.255.255.0 ! interface ...
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2answers
159 views

How to block youtube url on a cisco router

How can i block youtube on a cisco router? I have already used class map as seen below class-map match-any url-block-class match protocol http host "*youtube*" ! policy-map block-class policy-map ...
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1answer
29 views

Static routes to a server in packet tracer

If a generic server with 2 NICs has been added to the network in "packet tracer 7.2.1" where NIC-1 is part of VLAN-1 and NIC-2 is part of VLAN-2 of a layer 2 switch. How to statically route incoming ...
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2answers
32 views

How does a router know it's received an OLSR message?

So I'm working on my own routing protocol based on a alternative to IP, called ILNP, and I'm having trouble understanding how a router differentiates control packets and data packets for OLSR. The IP ...
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2answers
90 views

Are network protocols and routing protocols different things?

When reading about network protocols it says they are a set of rules and format for communication between devices over a network, so basically an agreed way of how to communicate over a network. But ...
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1answer
47 views

How to change ip TTL=1 on flat network for security [closed]

Working on a network at an high rise apartment complex. They have a core router/firewall acting as dhcp server and about 7 switches (all l3 switches). They have a few vlans to segment traffic based of ...
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1answer
45 views

Juniper MX/SRX series interface monitoring command

Good morning all, I was curious due to an issue were currently troubleshooting in our environment if there is a command in Juniper that will allow us to determine the utilization percentage of an ...
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1answer
84 views

Unable to configure SR-TE (Segment Routing Traffic Engineering) in CSR 1000v

I'm trying to configure SR-TE (Segment Routing Traffic Engineering) in CSR 1000v IOS XE 16 using the official tutorial in here Segment Routing Traffic Engineering (SR-TE) I have the same topology in ...
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1answer
35 views

What does the 'network w.x.y.z' RIPv2 command specify?

I'm studying networking protocols, and am starting with RIP. When configuring RIPv2, I see 2 pieces of information you need to relay to the router: Which interfaces to advertise RIP updates on Which ...
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1answer
52 views

Physical device in subnet of virtual networks [closed]

I was wondering if it's possible to connect a physical Raspberry to a NUC running several virtual machines on an ESXi environment. The network is setup as follows: I want my physical device to be '...
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1answer
34 views

VyOS: Failure to commit after L2TPv3 configuration

I am trying to get familiar with VyOS (using a VM) and while working on L2TPv3 I encountered something strange: after configuring the L2TPv3 interface and try to commit, an error occurs as if the ...
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0answers
39 views

Basic connectivity won't work in Packet Tracer

I've been redoing this multiple times and I'm sure i configured it correctly, however there is nothing happening at all. It's just a basic network with 3 routers and OSPF configured. Here are the ...
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0answers
68 views

Ad hoc vs Mesh, which one to use?

Say we have four nodes (A, B, C, D) that are arranged in a chain-like topology. A <-------> B <-------> C <-------> D Only the adjacent nodes are in range of one another (A can ...
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1answer
35 views

How does packet traversal works over a public network with NAT overloading

Let's say I have a private network connected to the internet with default gateway 192.168.1.1 on Router1. Now a host(Host#1, 192.168.1.10) on this network wants to send a packet over the public ...
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0answers
59 views

Is this a valid OSPF topology?

In the following topology: every Backbone router is an ABR. Router 2 belongs to three different areas, area 0, area 1, and area 4. is this a valid topology for OSPF ? it works as expected and it ...
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1answer
57 views

Resource Errors on 1G interfaces in Juniper router

We are observing resource errors on almost many 1G links on Juniper MX240. The resource errors counter is quite high. The MPC type is MPC Type 1 3D. I am sharing the output of command 'show interface ...
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1answer
145 views

Juniper SRX320 Dynamic VPN, cannot route to Remote-Protected-Resource

Multiple VPNs setup with a Juniper SRX320. The SRX320 has an irb interface as follows: irb { unit 0 { family inet { address 192.168.120.1/24; } } } I've setup ...
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1answer
65 views

Connecting eBGP and iBGP routers in Quagga

I am trying to run intra and inter-domain routing using Quagga. I like to announce a prefix from AS7 and I like AS6 receive it and send it to AS2(as shown in the attached topology). I know for intra ...
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2answers
81 views

InterVLAN routing issue

I've got one L3 Quanta switch. Having a bit of trouble in understanding the right way to configure VLANs and inter-VLAN routing on it. Routing on the switch is enabled. Ports 0/3 - 0/40 are ...
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1answer
34 views

Which device initiates the data exchange in OSPF (is it the master device or slave)?

I want to know which device initiates the data exchange in OSPF protocol (master device or slave device).
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1answer
63 views

How to transition an unauthenticated OSPF area to an MD5 authenticated area on a Cisco?

I currently have an existing OSPF area that has neighborships and is exchanging routes, but has no authentication mechanism. Is there a way to transition it to an MD5 authenticated area without ...
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0answers
18 views

Why is static route being blocked by firewall? [closed]

I've been trying to get router to send specific traffic over to my server to go through an OpenVPN connection. The OpenVPN connection is working fine; and I can use the server as a gateway with no ...
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0answers
385 views

pfSense: Route traffic from LAN to OpenVPN client

I have set up OpenVPN on pfSense, and it works almost the way I want it. The client connects to the pfSense box from the WAN, is assigned a tunnel IP and can communicate with all the networks on the ...
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1answer
18 views

ICMP echo messages in a network not properly configured

I have the following network It is really a simple network and routing table of both routers consist of directly connected networks only, meaning, no routing is being done here. Now, it is obvious ...
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0answers
93 views

Where is the traffic going?

Here is a routing puzzle: I'm working on a poorly documented network, and I'm trying to document things as I discover them. R1 is a core L3 switch. R2 is a router. The FW is a, well, firewall. On ...
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2answers
352 views

Default gateway of host connected to two routers via switch

I wanted to make this network fully connected, so I need to assign IP addresses to all interfaces of routers and to all hosts. However, I should assign a default gateway address to every host, but, ...
2
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1answer
200 views

Successful Intervlan Routing on a Layer 3 Switch, Unsuccessful IP Routing

Hello and thank you in advance for your help! I'm using Packet Tracer for testing purposes and I' m trying to implement a simple intervlan routing in a Layer 3 Switch (3560-24PS) and an IP Routing. ...
6
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1answer
1k views

Dealing with IP Spoofing

Border routers, which are routers that span two or more sub networks, can be configured to block packets from outside their administrative domain that have source addresses from inside that domain....