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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1answer
2k views

Does normal packet flow within a virtual router in a PA firewall require a rule?

I'm trying to understand packet flow within a Palo Alto firewall. Our firewall has one "inbound" leg and three "outbound" legs corresponding to different exterior VLANs. The exterior VLANs are used ...
4
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1answer
640 views

Do MVNOs have their own PGWs?

In mobile networks, there is this thing called PGW, which acts as the gateway between the internet and the internal network of the operator. (From the user's perspective, this could be seen as the ...
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2answers
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ISP edge router configuration

I need to configure Cisco 2901 router to route between interconnect block and usable ip block. Circuit is fiber 30Mb/s I got this info from ISP provider: IP space: Interconnect block - 50.204.xxx.80/...
5
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1answer
6k views

Juniper - eBGP change next-hop on advertised routes

unable to advertise a route to ebgp peer and modify next-hop address. on receive router this can be resolved by configuring a import policy that matches on community and sets next hop to proper ...
8
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2answers
6k views

Is there an SNMP MIB for Cisco Track Objects

My goal is to write a service check that pulls the status of a Cisco track list that is performing a Boolean OR. I have a screen scraper in place currently, but that is really not ideal in terms of ...
0
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1answer
279 views

Confuse about MTU(Maximum Transmission Unit) values [duplicate]

I have an Internet connection, I'm facing some difficulties in specific website loading that contain some large amount of data. If I download some files on the Internet the data will split into ...
2
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1answer
375 views

Internet Protocol. Source Routing. RFC 791. Are the addresses in the Source Routing option 1-indexed?

I was reading pages 18-21 in RFC 791 about the Internet Protocol and in the sections on Loose Source and Record Route (LSRR), and Strict Source and Record Route (SSRR), and Record Route (RR) it says ...
7
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1answer
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Configuring a Cisco ASA 5505 for routing

I'll start by pointig out that networking issues have always left me scratching my head. There is something about routing especially that I just haven't had that "Oh I get it" moment yet, so it's ...
4
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1answer
2k views

Screen to Junos “Set route …” command

tell me please how to translate the following Screenos to Junos... Do I understand correctly that the path to route 80.70.128.142/32 is via vrouter "UntrustGi-vr" ? Screenos command: set vrouter "...
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0answers
31 views

IPSEC over VRF lite? [duplicate]

I wanted to bounce an idea off of the community regarding the security of VRFs. I am looking to deploy 3 routers with switches modules built into them at three different physical locations. These ...
9
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1answer
545 views

How to provide failover for space-diversity T1

I have inherited a small, insular, dedicated network which is essentially trouble-free, so naturally I want to improve it :-) I lowered my network knowledge and savvy to somewhere around a 2 to 3 on ...
8
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1answer
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Cannot Load Internal Website over MPLS

We have an MPLS set up between two subnets. Everything (that is, I have RDP both directions as well as file-sharing) seems to be working correctly except for two things, which may be related. ...
6
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1answer
777 views

BGP, multipathing, and possibly OSPF

I'm setting up a second site for redundancy and DR. The goals are as follows: ISP fault-tolerance from either site: HostA, for example, can reach the internet in the event that ISP-A(primary) and ...
2
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2answers
344 views

Help with bringing DR site in to general network

I hope I can get some help as I've been wracking my brain to figure out the best way to get a new MPLS connection set up between our main site and our DR site. I'll first give a description of what I ...
4
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1answer
1k views

OSPF/BGP/Route-Map issue

hello to all my friends... i configured this scenario but R1 only traces until 10.10.13.3 (R3) ! plz help me... All routers have a loopback 0 interface X.X.X.X/32 where X is the number of the ...
22
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4answers
65k views

Why must all areas connect to an Area 0 backbone in OSPF?

This question is a literal repost of the same question asked on The Cisco Support Community. Answers are unique to Stack Exchange. Why is area 0 the backbone area in OSPF? Why must all other areas ...
4
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2answers
8k views

How do Metropolitan Area Networks (MAN) interconnect?

If an organization in a city (perhaps New York) has multiple offices within that city, how would they interconnect their LANs? I already understand that they will connect to an ISP, but my question is:...
6
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2answers
572 views

MPLS can reroute, but can it route?

I have 4 Cisco routers, connected one to another like the following: **R1**(s1/0)--(s1/0)**R2**(s1/1)--(s1/0)**R3**(s1/1)--(s1/0)**R4** All of them have an IP address assigned on their interfaces. ...
11
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2answers
3k views

How can ISPs on one continent connect to ISPs on another continent?

How can ISPs on one continent connect to ISPs on another continent? From a physical layer standpoint? Say one ISP is located in Asia and another one in Europe how would they connect their fiber ...
2
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1answer
135 views

Can link state routing protocols have more than 2 levels?

The CCNA book seems to imply only 2 levels possible under OSPF and IS-IS; I am curious as to if that was all you could do or if you could have further sublevels. Can link state routing protocols ...
6
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2answers
6k views

Traffic from route-map to crypto-map

This is sort of an offshoot of my previous question Ipsec vpn, phase 2 unable to come up. The VPN is up and working but now I'm having an issue with getting the right traffic across it. The only ...
2
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2answers
188 views

Adding a secondary route non-stackable switch group

I believe I am missing something obvious. I am using GNS3 to lab out having two paths to a CORE network. See picture. The configuration works as I imagined, I can ping from each Switch every other ...
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1answer
1k views

RIP Update Packets

How Many Routes Can be carried by a RIP Version 1 & RIP Version 2 Update Packets ? I Know Both RIP Version 1 & 2 Using the Metric of Hop Count and Maximum Hop Count is 16.
5
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2answers
202 views

Locating a single IPv6 or IPv4 routable prefix at multiple data centers

Academic question (at the moment): Is it possible to advertise BGP routes to a given prefix (IPv6 and/or IPv4) from multiple different physical data centers? I guess this is multi-homing, but ...
5
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1answer
14k views

Sonicwall NSA 2600 routing issues with multiple LAN interfaces configured

We have a Sonicwall NSA 2400 that has been in service for some years now. We've never had an issue with any routing until we "upgraded" to a new NSA 2600 device. Below is a rough idea of the ...
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2answers
6k views

Why is the target IP address always my default gateway?

I am currently researching ARP packets using Wireshark and have found that when I ping a new computer asking for the MAC address that corresponds with the known IP address, my target IP address in my ...
5
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3answers
15k views

Stuck at GRE troubleshooting with recursive route

As with my last question, I am learning for my CCNA exam and currently I am bashing my head against the wall, while trying to solve "7.2.2.4 Troubleshooting GRE" I'll explain the topology in a second....
4
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2answers
1k views

Path MTU discovery and retransmission

I'm reading about IP at the moment and one thing I haven't been able to comprehend very well, is the retransmit situation for IP packets with DF set. In this situation, I assume the following happens ...
2
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1answer
1k views

Destination NAT based IP SLA Trigger

Can the destination address be changed by using outside NAT? Routing protocols cannot be changed. Here is my network:
4
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1answer
735 views

Dual stack OSPF redistribution in MP-BGP

My topology is working perfectly fine and is as follows: CE1 <-> PE1 <-> P1 <-> P2 <-> PE2 <-> CE2 CE1 <-> PE1 and CE2 <-> PE2 are having OSPFv3 with ...
13
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2answers
9k views

What is a non-portable IPv4 address block?

For example, a Whois query for 4.4.4.0 says: ADDRESSES WITHIN THIS BLOCK ARE NON-PORTABLE Does the owner simply declare the block or a subnet are not up for sale? Or does non-portable have a ...
11
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2answers
4k views

Why is RIP not scalable?

Most of the references say "RIP is not scalable" hence can be used only in smaller networks. But none say "WHY?" What is that in RIP that actually preventing it from scaling to larger networks? And ...
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4answers
6k views

When a ping is lost, what happens?

Suppose that the message you are sending does not reach the destination, such as a ping. Is the content of that message protected? How is a retransmission accomplished?
9
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2answers
18k views

Learned eBGP routes not distributed to iBGP neighbors

I have (in GNS3) three Cisco 3640s running 12.4(23) connected in series (R1 -> R2 -> R3). R1 and R2 are eBGP peers, R2 and R3 are iBGP peers. R1 advertises network 192.168.1.0/24. R2 receives this ...
6
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1answer
3k views

Network not participating in OSPF. Does not appear in the routing table

I am running OSPF on 2 router in GNS simulation for practice. Adjacencies are ok. Router R2 has in the routing table all networks of R3 . But R3 fails to add R2 network in its routing table . The ...
9
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2answers
2k views

BGP Autonomous System Path Duplicate AS

Is it normal to see a path as such in my BGP update ? 12 34 33 2 2 45 331 As I can see from the path above, AS number "2" appears twice ! Is it normal ? Are they any scenarios that could have made ...
8
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1answer
2k views

SubInterface on a router

How many sub interfaces can be created on a cisco router to route between vlans on a connected switch?
3
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1answer
1k views

Cable modem ARP behavior [closed]

I have three layer 3 devices in a pretty simple topology: PC1 -> [Fe0/0] C2621 [Fe0/1] -> [Fe0/2] Modem [WAN] -> Internet PC1: 192.168.254.100/24 C2621: Fe0/0: 192.168.254.254/24 ...
3
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0answers
441 views

Policy Based Routing (not matching packets) - Virtual Template

I have this configuration runnning : Larger image I tested the policy based routing int the lab using two linksys router acting as ppp clients of the Cisco 7206VXR and another linksys emulating the ...
5
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1answer
526 views

Loop Prevention in AODV

we're supposed to do a presentation on AODV, and even having read all the official documentation and some additional sources, we're stumped by the question of how sequence numbers prevent loops. ...
2
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2answers
1k views

Routing Issue - Can't access internet and home lab at the same time

I'm trying to setup a home lab to study for a Cisco certification. My problem is I'm tired of having to physically plug the console into a different device every single time I want to configure it by ...
3
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1answer
2k views

Static routes between 3 windows routers and vyatta

Hi for a school project I have to build a network this is the current situation: I can ping between 172.16.0.0/19, 172.16.32.0/19 and 172.16.64.0/19. I can ping from my router (172.16.128.15) to ...
4
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1answer
1k views

Routing to public IPs behind firewall with VPN

I have two sites. Site 1 has a router with a public IP A.B.C.D as well as a private range 192.168.13.0/24. The router also occupies the private IP 192.168.13.1. Site 2 is a single host with a public ...
12
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1answer
4k views

Is it possible to connect two private eBGP peers with the same AS number?

The Problem A third party has implemented a small network and private BGP setup within one of our branches. We need to setup a eBGP peer relationship with this network. However we are both using the ...
9
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1answer
2k views

Summarized OSPF routes advertised?

Preparing for CCNP, doing some lab work. ZEUS is summarizing two loopbacks with area 2 range 172.16.2.0 255.255.254.0, and the summary route is arriving on router 'WODAN' but the subordinate routes (...
6
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3answers
6k views

OSPF Area Backbone(0) is Inactive

I am having a puzzling issue with OSPF connectivity on one of my routers. The other routers in my network have formed an adjacency and are working correctly, but this last one is a case I've never ...
11
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1answer
3k views

After TCP is established which BGP peer will send open message first?

After a Tcp connection is established between two bgp peers. which peer will send the open message first ? the active peer(which is initiating outbound connection) or the passive peer?(peer which is ...
11
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3answers
1k views

Quagga routing and security

I have a quagga router with two transit neighbors and announcing my own IP space. I recently joined a public peering exchange (IXP) and so I'm part of their local network (/24), together with all ...
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1answer
141 views

Can we assign Autonomous System Number in other way than BGP?

Can I assign an Autonomous System Number in other way than BGP?
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1answer
4k views

Routing throughput of an L3 switch

The Cisco SG300-10 says its forwarding rate is 14.88Mpps with 64 byte packets. I estimated this to be ~ 7 Gb/s. Does this mean that up to 7 computers can transfer data across VLANs at full 1 Gb/s ...