Networking Protocols

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Networking software modules are interfaced with a framework implemented on the machine's operating system that implements the networking functionality of the operating system. The best known frameworks are the TCP/IP model and the OSI model. Systems typically do not use a single protocol to handle a transmission. Instead they use a set of cooperating protocols, sometimes called a protocol family or protocol suite.[9] Some of the best known protocol suites include: IPX/SPX, X.25, AX.25, AppleTalk and TCP/IP. Other protocols indirectly related to networking include the hypertext transfer protocol (HTTP) and its related technologies, Dynamic Host Configuration Protocol (DHCP), Domain Name Server (DNS) and other Internet protocols.

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My server admin is asking of me to open up 1000 ports for a server to run passive FTP. Is there any other way to have passive FTP without opening up all those ports?
What concerns should I be aware of security wise in doing this?
0
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Screen-Shot-2017-10-16-at-9.01.37-PM.png
in the topology above , I  configured on R3 area 1 as stub in the first LAB then configured the same area 1 as NSSA in the second LAB.
In matter of OSPF Routing table Stub or NSSA the effect is the same , both have made R2 and R1 unable to reach any interface of R3 and the other way around also is true.

In matter of LSDB there was difference,, NSSA has created LSA type 7 on R3 area 1  

***My question is what's the purpose of LSA 7 if OSPF routing tables gave the same results between  , when I configured area 1 as Stub then NSSA ?


the output below is when I configured area 1 NSSA on R3

R1#sh ip route ospf 
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route, + - replicated route

Gateway of last resort is not set

      2.0.0.0/32 is subnetted, 1 subnets
O        2.2.2.2 [110/2] via 192.168.12.2, 00:00:45, FastEthernet0/0
O IA  192.168.23.0/24 [110/2] via 192.168.12.2, 00:00:45, FastEthernet0/0
R1#

Open in new window


R2#sh ip route ospf 
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route, + - replicated route

Gateway of last resort is not set

      1.0.0.0/32 is subnetted, 1 subnets
O        1.1.1.1 [110/2] via 192.168.12.1, 00:03:24, FastEthernet0/0
      11.0.0.0/24 is subnetted, 1 subnets
O E2     11.11.11.0 [110/20] via 192.168.12.1, 00:03:24, FastEthernet0/0
R2#

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R3#sh ip route ospf 
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route, + - replicated route

Gateway of last resort is not set

R3#
R3#

Open in new window


Thank you
1
I have :

R1---R2---R3

OSPF is configured at the Global configuration level on all routers.

R1  has 2 loopbacks: loopback0 (1.1.1.1/24) and loopback1 (11.11.11.11/24)
R1 has interface fa0/0 (192.168.12.1) connected to R2

Router OSPF 1
Network 1.1.1.0 advertised into area 0
Network 192.168.12.0 into area 0

** 11.11.11.0 network is not advertised, it is redistributed

R2 has loopback 2.2.2.2/24
R2 has interface fa0/0(192.168.12.2) connected to R1
Network 2.2.2.0 advertised into area 0
network 192.168.12.0 avertised into area 0

R2  has also interface fa0/1(192.168.23.2) connected to R3
so R2 has advertised Network 192.168.23.0/24 into area 1

***Let 's not worry about R3 , since it has all its interfaces in area 1

Now on R1 : I have "redistribute connected subnets"
this has redistributed the prefix 11.11.11.0 into area 0

Well, when I check R1 ospf routing table there is no prefix 11.11.11.0 , it shows on its global routing table as directly connected.

on R2, the prefix 11.11.11.0/24 shows as E2.

My question now is why in R1 the prefix 11.11.11.0 is not showing as E2 ?

Sorry I have my topology and configuration in the Lab , this is why I cannot paste the topology and/or the configuration.

Any clarification will be very much appreciated.

Thank you.
0
What are some good VPN software or services that will allow me to use the same external IP address every time and also change to different external IP addresses around the world whenever I need to?

I need to be able to use this both within Windows 10 and the latest Mac OS X software.
0
Hello I have a digital signage software server to remote led screens ..its   a web sever run on port   777  and 5222 it was work fine for few months my puplic ip was started by .195.xxx.xx.xx but now  it's stop i cant ping my pulic ip and all the ports is closed when I checked them by can you see me . Com now my public ip start by 63.xx.xx.xx what I can do to run the server again


Thank you
0
Around the time some of our traffic dipped to our site - I saw a number of changes of BGP path with lots of prepended AS's indicating less preferred routes. If those changes were beyond our directly connected ISP, what is the best way to find out why the path changed at that time? Is there a way to find out? There were perhaps 10 path changes in 10 minutes before things got back to normal.
1
I’m new to VLANs and I’m trying to set some up on our school’s network. I think my aims are simple, but I’m having problems.  Here’s a simplified diagram showing the topology.
St_dominics_network_extract3-help--1.jpg
Currently, everything is on 192.138.1.0/24.  I’m trying to split this into 4 VLANs, using the Layer 3 features of the SG300 rather than involving the Sonicwall (other than as a gateway).  My goal is that PCs on any VLAN can access only the web and the domain controller.  The DC will provide DHCP via a relay/helper address.

I’m starting with VLAN 100, to which I’ve assigned 192.168.100.1/24 (in the SG300).  I’ve set up the same VLAN in my SG200 switch (Layer 2).  The immediate problem is that VLAN 100 interface can only be pinged from within the SG300. Not from the SG200 or the DC.  

The Switch ports are set up like this:

SG200
40: Access (test PC)   VLAN1:excluded   VLAN100:untagged
48: Trunk (to sonicwall)  VLAN1:untagged   VLAN100:tagged
49: Trunk (to SG300)   VLAN1:untagged   VLAN100:tagged

SG300
2: trunk (to SG300)   VLAN1:untagged   VLAN100:tagged
9: trunk (to DC)  VLAN1:untagged   VLAN100:tagged      

Other SG300 settings
IPv4 interfaces:  VLAN1: 192.168.1.229   VLAN100: 192.168.100.1
IPv4 static routes:   Dest IP prefix: 0.0.0.0   next hop router ip: 192.168.1.200
DHCP:  relay:enabled  DHCP snooping status: enable   DHCP server IP:192.168.1.10

I haven’t made any changes to the Sonicwall router. I’m not sure whether I need to, or even whether it would…
0
We have AT&T MIS 10Gbps Ethernet circuit with speed throttled to 2Gbps. We have 10Gbps fiber connection from AT&T router to our fortinet firewall 600D 10G port. Is their a way to test internet speed over 1Gbps? We don't have any device or NIC with more than 1 Gig. How to test it?
0
using asa 5516 9.5

I want to block one host (for ex. 192.168.1.100) so that is unable to get outside at all including the obvious 80 and 441. Will I still have access to it internally? I just want to make sure I'll have all access for inside to it. the below does not have the "eq www" which only blocks internet.

If I do :
access-list inside_in extended deny tcp object-group SERVER_BLOCK any4 

Open in new window


SERVER_BLOCK = 192.168.1.100

Will I be OK?
0
Dear wizards, my router was hang this afternoon. Internet for email system was interrupted for about 20 mins. we could not telnet or connect to it via console port, and had to reset the router to bring it back.

so how can we know what happened? where can we find the logs? was it a signal of DDoS attack? and if so, how can we mitigate it?
0
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Hello,

Two days ago I tried to print a PDF file to a networked printer and nothing happened.  It is like the printer disappeared.  I did some digging and found a new error in Device Manager - my Microsoft Teredo Tunneling Adapter had a yellow exclamation that said the device cannot start (Code 10).  

I tried disabling and re-enabling the adapter, no luck.  I did the same for my physical NICs on my PC and no luck.  I was able to get my printer to work, but now a screen capture utility called SnagIt 9 no longer displays the library of my screen captures (many thousands).

Here is info on my system:

Windows 7 Pro 64-bit
Up to date with Microsoft updates
Have three physical network interface cards in the PC, two are disabled - only one used
For all three cards, IP4 and IP6 are checked

I tried having Device Manager check for driver updates, and was told I have the latest version.  I also uninstalled the adapter and re-installed it, but I still have this error message.  Any suggestions?
0
I am using file Zilla to connect an ftp server but unfortunately unable to do so below is the error

Status:      Resolving address of ftp2.churchs.com
06:38:14      Status:      Connecting to 209.208.247.23:21...
06:38:14      Status:      Connection established, waiting for welcome message...
06:38:15      Status:      Insecure server, it does not support FTP over TLS.
06:38:15      Status:      Logged in
06:38:15      Status:      Retrieving directory listing...
06:38:34      Command:      PWD
06:38:34      Response:      257 "/CFC-Analytics" is current directory.
06:38:34      Command:      TYPE I
06:38:34      Response:      200 Type set to I.
06:38:34      Command:      PORT 10,139,105,11,209,15
06:38:34      Error:      Disconnected from server: ECONNABORTED - Connection aborted
06:38:34      Error:      Failed to retrieve directory listing
0
Hello, so this firm has a Windows Server SBS 2011 which is mainly used for Exchange and for sharing purposes.

Lately one strange problem has emerged: you open a file from a client (the file is on the server and shared) and you get the usual warning about someone else using the file right now, the file is read-only and so on.

Mind you, I'm not talking about a particular file, this can happen with any file actually.

Problem is, the file is not being used by anyone else, we have verified this many times.
After a while, it will just "unlock" and became fully available.

So, does anyone know how to address this problem or try to diagnose it? It never happened to me in many a year. Thanks.
0
I am trying to see what the best way to assign vlans to my subnets. The below is what I was planning for with the 3rd octet as the vlan#:
- vlan 8 - 10.10.8.0/22 (10.10.8.1 - 10.10.11.254)
- vlan 18 - 10.10.12.0/22 (10.10.12.1 - 10.10.15.254)

But now we are breaking 10.10.8.0/22 to the below. Any tips on assigning the vlan #?
vlan8 - 10.10.8.0/28
vlan? - 10.10.8.16/28
vlan? - 10.10.8.32/27
vlan? - 10.10.8.64/26
0
Please help me understand about ARP.
I know the local ARP table is cached and records also can be manually added. But how come when I ping a remote IP it doesn't automatically create a corresponding ARP table record?
0
Hello ,

I have 2 questions about timestamp ;

1. I have try to convert time stamp value to normal time but it was returned anormal dates :) what is the format of this TS val ?
2. As far as i read on the http://www.networksorcery.com/enp/protocol/tcp/option008.htm 


This field is only valid if the ACK bit is set in the TCP header.


but nearly all SYN packets in normal traffic not a DDOS has TSval  while ack was not sScreen-Shot-2017-08-27-at-18.05.41.pnget
0
show ip pim nei
PIM Neighbor Table
Mode: B - Bidir Capable, DR - Designated Router, N - Default DR Priority,
      P - Proxy Capable, S - State Refresh Capable, G - GenID Capable


Neighbor          Interface                Uptime/Expires    Ver   DR
Address                                                                                                 Prio/Mode
10.0.0.193        TenGigabitEthernet1/2    11w1d/00:01:29    v2    1 / S P G
10.0.0.209        TenGigabitEthernet3/1    11w0d/00:01:41    v2    1 / S P G
10.0.16.13        TenGigabitEthernet4/7    11w2d/00:01:25    v2    1 / G
10.0.16.9         TenGigabitEthernet4/8    11w2d/00:01:27    v2    1 / G


What does it mean when I only have the G in the mode column?

The link at 4/7 and 4/8 is eBGP peer.
0
Hi All,

I am having problems loading OS image onto a new Nexus 9504 with 2 sup below are the steps i have tried, any advise would be much appreciated. image i am using is nxos.7.0.3.I5.2.bin

1. Reload switch and
2. Ctrl + C
3. cmdline recoverymode=1 and cmdline init_system
4. boot nxos.7.0.3.I5.2.bin (which is copied on bootflash/)
5. After this it starts configs and took some time but displayed other messages: System is coming up ... Please wait ...
6.After this, it returns to bash shell: bash-4.2# and nothing happens
7. Both switches, I have reloaded twice and retied again; but still same.

when i exit it takes me into (standby) login: but requires username and password which i have tried all the defaults and will not let me in.

Thanks
0
Hi Sir,

Would like to ask for your help about the problem listed below,

[Tunnel Authorize Fail] ignoring Delete SA payload: PROTO_IPSEC_ESP SA(0xccb797a8) not found (maybe expired)

Hoping that you can help me resolve this matter.


Thank you in advance.
0
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Is this a mistake or  am i  checking sth wrong , how should be a packet with missing checksum ?

0000   a0 36 9f 55 7c aa dc 38 e1 ac 9b 89 08 00 45 00  .6.U|..8......E.
0010   00 25 8b cb 00 00 fd 11 d7 aa 89 3c 5a 64 b9 b6  .%.........<Zd..
0020   bc fa fc 5d 69 87 00 11 00 00 ff ff ff ff 55 38  ...]i.........U8
0030   55 76 03 00 00 00 00 00 00 00 00 00              Uv..........

Open in new window


Screen-Shot-2017-08-13-at-17.28.06.png
0
I am using this Arris NVG443 router in conjunction with an Obitalk 200 to use internet (DSL)  VOIP to make and receive phone calls. The problem is no matter what service I use ie. Google voice (free), Onesuite (subscription),  ALL calls made and received drop within minutes. Using Onesuite provider  all calls drop at exactly 9 minutes every time. Obitalk support says to configure my router to this:
In order for your OBi to be able to send packets w/o interruption, please configure your router as follows:

Allow Outgoing:
TCP Ports: 6800, 5222, 5223
UDP Ports: 5060, 5061, 10000 to 11000, 16600 to 16998, 19305
Allow Incoming on UDP Port: 10000

Problem is: There is nowhere to enter all these ports? Just one range.
 Router has port forwarding and port triggering . In port forwarding there is only a global port range  one port # to another port #, and one base port.
In port triggering there is just a trigger range same as above, one port to one port, and one open port range same as above.

Not sure what to enter into router and can't seem to find any answers ?
0
Dear Team,

There is port already open between  Source -target servers.
i have tested the same using telnet command.

However while I am creating some Datasource in Application server, i am getting  the above error message.

Kindly let me know if there anything required  at OS/App servet/network side .

Kindly advice
=== ERR MESSAGE IS =========
>
<Aug 7, 2017 4:52:24 PM AST> <Warning> <Deployer> <BEA-149004> <Failures were detected while initiating activate task for application 'test'.>
<Aug 7, 2017 4:52:24 PM AST> <Warning> <Deployer> <BEA-149078> <Stack trace for message 149004
java.rmi.RemoteException: [Deployer:149150]An IOException occurred while reading input.; nested exception is:
        java.net.NoRouteToHostException: No route to host
        at weblogic.deploy.service.internal.transport.http.HTTPMessageSender.sendMessageToServerURL(HTTPMessageSender.java:343)
0
Screen-Shot-2017-08-06-at-11.30.59-A.png
on the topology above , I have R1 and R6 on AS 1, R5 on AS3 , R2,R3,R4 on AS2

I would like to have Routers on AS1 (R1 and R6) Not take route through AS3 to reach routers inside AS2, instead I want AS1 routers to go straight to AS2 through R1 using BGP Default Local Preference command on R1

you can see in the config below on R1 :
bgp default local-preference 600


Below is the BGP route configuration on R1, R6, R3. As you can see R6 is going through AS3 to reach routers in AS2 instead of going straight to AS2 through R1

If you need more info , please feel free to ask.


Thank you

R1#sh run | beg router bgp
 bgp default local-preference 600
 network 1.1.1.0 mask 255.255.255.0
 neighbor 192.168.12.2 remote-as 2
 neighbor 192.168.16.6 remote-as 1

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R6#sh run | beg router bgp
router bgp 1
 no synchronization
 bgp log-neighbor-changes
 neighbor 192.168.16.1 remote-as 1
 neighbor 192.168.56.5 remote-as 3

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R5#sh run | beg router bgp
router bgp 3
 network 5.5.5.0 mask 255.255.255.0
 neighbor 192.168.35.3 remote-as 2
 neighbor 192.168.56.6 remote-as 1

Open in new window


R1# sh ip bgp
BGP table version is 13, local router ID is 1.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*> 1.1.1.0/24       0.0.0.0                  0         32768 i
* i2.2.2.0/24       192.168.56.5             0    100      0 3 2 i
*>                  192.168.12.2             0             0 2 i
* i3.3.3.0/24       192.168.56.5             0    100      0 3 2 i
*>                  192.168.12.2                           0 2 i
* i4.4.4.0/24       192.168.56.5             0    100      0 3 2 i
*>                  192.168.12.2                           0 2 i
* i5.5.5.0/24       192.168.56.5             0    100      0 3 i
R1#

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R6#sh ip bgp              
BGP table version is 6, local router ID is 192.168.56.6
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*>i1.1.1.0/24       192.168.16.1             0    600      0 i
* i2.2.2.0/24       192.168.12.2             0    600      0 2 i
*>                  192.168.56.5                           0 3 2 i
* i3.3.3.0/24       192.168.12.2             0    600      0 2 i
*>                  192.168.56.5                           0 3 2 i
* i4.4.4.0/24       192.168.12.2             0    600      0 2 i
*>                  192.168.56.5                           0 3 2 i
*> 5.5.5.0/24       192.168.56.5             0             0 3 i

Open in new window



R5# sh ip bgp             
BGP table version is 10, local router ID is 5.5.5.5
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*> 1.1.1.0/24       192.168.56.6                           0 1 i
*> 2.2.2.0/24       192.168.35.3                           0 2 i
*> 3.3.3.0/24       192.168.35.3             0             0 2 i
*> 4.4.4.0/24       192.168.35.3                           0 2 i
*> 5.5.5.0/24       0.0.0.0                  0         32768 i
R5#

Open in new window

0
Need list of unencrypted protocols.

I know only port 80(HTTP) and 21(FTP)
0
Hi, I want to open connection from RHEL to FTPS server, receive "Fatal error: gnutls_handshake: A TLS packet with unexpected length was received" error when start to transfer file to the FTPS server.

Any idea?

 lftp -v
LFTP | Version 4.0.9 | Copyright (c) 1996-2010 Alexander V. Lukyanov

LFTP is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with LFTP.  If not, see <http://www.gnu.org/licenses/>.

Send bug reports and questions to the mailing list <lftp@uniyar.ac.ru>.

Libraries used: Readline 6.0


FileCopy(0xbcd2c0) enters state INITIAL
FileCopy(0xbcd2c0) enters state DO_COPY
---- dns cache hit
---- Connecting to x.com (10.0.0.1) port 21
copy: get hit eof
copy: waiting for put confirmation
FileCopy(0xbcd2c0) enters state CONFIRM_WAIT
GNUTLS: HSK[0xbfc2c0]: Keeping ciphersuite: DHE_RSA_AES_128_CBC_SHA1
GNUTLS: HSK[0xbfc2c0]: Keeping ciphersuite: DHE_RSA_CAMELLIA_128_CBC_SHA1
GNUTLS: HSK[0xbfc2c0]: Keeping ciphersuite: DHE_RSA_AES_256_CBC_SHA1
GNUTLS: HSK[0xbfc2c0]: 

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0

Networking Protocols

11K

Solutions

16K

Contributors

Networking software modules are interfaced with a framework implemented on the machine's operating system that implements the networking functionality of the operating system. The best known frameworks are the TCP/IP model and the OSI model. Systems typically do not use a single protocol to handle a transmission. Instead they use a set of cooperating protocols, sometimes called a protocol family or protocol suite.[9] Some of the best known protocol suites include: IPX/SPX, X.25, AX.25, AppleTalk and TCP/IP. Other protocols indirectly related to networking include the hypertext transfer protocol (HTTP) and its related technologies, Dynamic Host Configuration Protocol (DHCP), Domain Name Server (DNS) and other Internet protocols.