cisco 1751 is doing half duplex instead of full

Posted on 2007-10-10
Last Modified: 2013-11-09
cisco 1751 router
one 10mb nic set to full duplex
one 100mb nic set to full duplex

hooked to a trendnet smart switch,  the switch port where the cisco hooks immediately goes to 10mb half.  If I try to change it to 10 full, it responds that the cisco is only doing half and the port must also do half.

the connection going out the other port goes to the our wan which is full.

why is the cisco doing half even though it is set to full?

Question by:javagair
    LVL 6

    Accepted Solution

    For what I remember, the 1751 has one fastethernet interface (10/100) and one ethernet interface for WAN connectivity (10 Half Duplex only by definition).

    Does that help ?

    Author Comment

    the 1750 come with only a 10/100 interface
    I added a 10mb wic 1enet which will do full

    I found out the the telco had set our line to half because the router we had in there was a 1600 and only did half.
    I called them and they went to full

    The problem is that only one of my 6 offices on this private telco network will the smart switch report that the cisco 1750 is talking to it at full duplex.

    so what it appears is that the telco side is full and my side is half, and it appears for no reason.
    all interfaces are set to full duplex on the router


    Author Comment

    these cards are nockoffs.
    1. they have copper solder points, cisco uses only silver
    2. were there should be one electrical part there are two
    3. the port is not cisco standard
    4. the writing on the cards does not fit in spaces aloted, and is on, not part of the board
    5. serial number are printed wrong
    6. words on chips are stamped on not etched as they should be

    they will not do duplex and they cause extreme packet loss.
    to conclude they are second rate junk, and from what I am hearing any cisco or any other card listed on Ebay from China or Hong kong are fakes.

    after we tried to use these cards and had major problems with our network, we started looking on the web for info on fake cisco equipment.
    check this site out.

    bought an authentic cisco card to compare these with and one can see the problems with the cards immediately.
    put the authentic cisco card into service, network problems went away!

    any one reading this needs to spread the word about not buying Chinese cards sold on ebay.

    live and learn I guess


    Featured Post

    Free Trending Threat Insights Every Day

    Enhance your security with threat intelligence from the web. Get trending threat insights on hackers, exploits, and suspicious IP addresses delivered to your inbox with our free Cyber Daily.

    Join & Write a Comment

    Suggested Solutions

    When posting a question about a Cisco ASA, Cisco Router or Cisco Switch, it can aid diagnosis if a suitably sanitised copy of the config is provided. It is much better to leave as much of the configuration as original as possible, as it could be tha…
    After creating this article (, I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…
    After creating this article (, I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…

    729 members asked questions and received personalized solutions in the past 7 days.

    Join the community of 500,000 technology professionals and ask your questions.

    Join & Ask a Question

    Need Help in Real-Time?

    Connect with top rated Experts

    19 Experts available now in Live!

    Get 1:1 Help Now