<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:st1="urn:schemas-microsoft-com:office:smarttags" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii">
<meta name=Generator content="Microsoft Word 11 (filtered medium)">
<!--[if !mso]>
<style>
v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style>
<![endif]--><o:SmartTagType
namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="country-region"/>
<o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags"
name="City"/>
<o:SmartTagType namespaceuri="urn:schemas-microsoft-com:office:smarttags"
name="place"/>
<!--[if !mso]>
<style>
st1\:*{behavior:url(#default#ieooui) }
</style>
<![endif]-->
<style>
<!--
/* Font Definitions */
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman";}
a:link, span.MsoHyperlink
{color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{color:blue;
text-decoration:underline;}
span.EmailStyle21
{mso-style-type:personal-reply;
font-family:Arial;
color:navy;}
@page Section1
{size:8.5in 11.0in;
margin:1.0in 1.25in 1.0in 1.25in;}
div.Section1
{page:Section1;}
-->
</style>
<!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang=EN-US link=blue vlink=blue>
<div class=Section1>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Yeah sorry I forget it is a 500 Express, u
cannot customize it. Will update us if u find any solution with cisco<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<div>
<div class=MsoNormal align=center style='text-align:center'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=2 width="100%" align=center tabindex=-1>
</span></font></div>
<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> Jefflin Choi
[mailto:jefflin.choi@gmail.com] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Thursday, July 05, 2007 4:12
AM<br>
<b><span style='font-weight:bold'>To:</span></b> Ahmed Elnagar<br>
<b><span style='font-weight:bold'>Cc:</span></b> cisco-voip@puck.nether.net<br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [cisco-voip] cisco IP
Phone causes stp loop.</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Problem now is seems like there is no way to disable portfast on CE500.<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Will have a conf call with our local cisco systems later. I'll push
them to fix this vulnerability.<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><br>
Thanks for all your help.<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>regards,<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Jeff<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><span class=gmailquote><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'>On 7/4/07, <b><span style='font-weight:bold'>Ahmed
Elnagar</span></b> <<a href="mailto:aelnagar@act-eg.com">aelnagar@act-eg.com</a>>
wrote:</span></font></span> <o:p></o:p></p>
<div>
<div>
<div>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:black'>I have just something came to my mind. in
old configuration of IP Telephony the attached port was configured to be trunk
not access port, maybe that could help in solving this here is the
configuration: </span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> switchport trunk encapsulation dot1q<br>
switchport mode trunk<br>
switchport voice vlan 2<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>this puts the voice traffic in vlan2. If u need to create data vlan
just change the native vlan on that trunk to whatever u want. the delay that u
r talking about when portfast is disabled only happens one time when powering
on the devices that connect to the switch and if it is going to work this delay
will be much more better than having a loop in the network. <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color="#003366" face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma;color:#003366'>Thanks and Best
Regards<br>
<b><span style='font-weight:bold'><br>
Ahmed A. Elnagar<br>
</span></b>Network Engineer </span></font><font size=2 color=black face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma;color:black'>Specialist</span></font><o:p></o:p></p>
</div>
</div>
<div>
<div>
<div style='margin-top:5.0pt;margin-bottom:5.0pt'>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div style='margin-top:5.0pt;margin-bottom:5.0pt'>
<p class=MsoNormal><font size=2 color="#003366" face=Tahoma><span lang=ES
style='font-size:10.0pt;font-family:Tahoma;color:#003366'>Advanced Computer
Technology (ACT)<br>
16 Fawzy Ramah St.Off Shehab St.Mohandessin, Giza, Egypt <br>
Postal Code:12411 Cairo Egypt <br>
</span></font><font size=1 color="#003366" face=Tahoma><span style='font-size:
6.0pt;font-family:Tahoma;color:#003366'><br>
</span></font><b><font size=2 color="#003366" face=Tahoma><span lang=ES
style='font-size:10.0pt;font-family:Tahoma;color:#003366;font-weight:bold'>Mob</span></font></b><b><font
size=2 color="#003366" face=Tahoma><span style='font-size:10.0pt;font-family:
Tahoma;color:#003366;font-weight:bold'> :</span></font></b><font size=2
color="#003366" face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma;
color:#003366'> +2010-2833868</span></font><font size=2 color=black
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma;color:black'><br>
</span></font><b><font size=2 color="#003366" face=Tahoma><span lang=ES
style='font-size:10.0pt;font-family:Tahoma;color:#003366;font-weight:bold'>Website</span></font></b><b><font
size=2 color=black face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma;
color:black;font-weight:bold'>: </span></font></b><font size=2 color="#003366"
face=Tahoma><span lang=ES style='font-size:10.0pt;font-family:Tahoma;
color:#003366'><a href="http://www.act-eg.com/" target="_blank">www.act-eg.com</a><br>
<b><span style='font-weight:bold'>E-mail</span></b></span></font><b><font
size=2 color="#004600" face=Tahoma><span style='font-size:10.0pt;font-family:
Tahoma;color:#004600;font-weight:bold'>: </span></font></b><font size=2
color="#003366" face=Tahoma><span lang=ES style='font-size:10.0pt;font-family:
Tahoma;color:#003366'><a href="mailto:aelnagar@act-eg.com" target="_blank">aelnagar@act-eg.com</a></span></font><o:p></o:p></p>
</div>
</div>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<div class=MsoNormal align=center style='text-align:center'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=2 width="100%" align=center>
</span></font></div>
<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> <a
href="mailto:cisco-voip-bounces@puck.nether.net" target="_blank">cisco-voip-bounces@puck.nether.net</a>
on behalf of Jefflin Choi <br>
<b><span style='font-weight:bold'>Sent:</span></b> Wed 04-Jul-07 12:30 PM<br>
<span class=q><b><span style='font-weight:bold'>To:</span></b> <a
href="mailto:cisco-voip@puck.nether.net" target="_blank">cisco-voip@puck.nether.net</a></span><o:p></o:p></span></font></p>
<div><span id="q_1139101c10b34543_6">
<p class=MsoNormal><span class=e><b><font size=2 face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma;font-weight:bold'>Subject:</span></font></b></span><span
class=e><font size=2 face=Tahoma><span style='font-size:10.0pt;font-family:
Tahoma'> Re: [cisco-voip] cisco IP Phone causes stp loop.</span></font></span><font
size=2 face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'><br>
<br>
<o:p></o:p></span></font></p>
</div>
</span>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><br>
<o:p></o:p></span></font></p>
</div>
<div><span id="q_1139101c10b34543_8">
<div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Got this reply...<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>========<br>
As far as i know, no solution exists for this race around condition. <br>
<br>
If two "port fast" enabled ports are looped, it will create a mess in
the network. <br>
Because the switch will never send a BPDU via a port fast enabled port. Hence
there is no way the switch can detected that both the ports are looped. <br>
It is better to disable the port fast in this scenario. <br>
If you encounter any solution, kindly keep us all posted. <br>
=======<br>
<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><strong><b><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'>Problem is</span></font></b></strong>, if portfast is
disabled, pc's/phones uptime will be delayed. This is also in conflict with
cisco's SRND of enabling portfast.<o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>There should be some way to work this out. Any ideas?<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Thanks,<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Jeff<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><span class=gmailquote><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'>On 7/4/07, <b><span style='font-weight:bold'>Jefflin
Choi</span></b> <<a href="mailto:jefflin.choi@gmail.com" target="_blank">jefflin.choi@gmail.com
</a>> wrote:</span></font></span> <o:p></o:p></p>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Hi Lee,<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>BPDU Guard is enabled by default as far as i know on CE500. <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>This has come into my mind and checked the switch thus the reason why i
ask if the IP Phone is sending BPDU. If not, BPDU guard will be just useless.<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><br>
Anyway, checking cisco netpro forum, someone has encountered the same issue.
Unfortunately no resolution.<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>The reply was:<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>"Question1: Yes, IP phones donot send BPDU's.You can enable BPDU
guard and it does not shut the port down when an IP Phone is connected. "<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Any ideas how to overcome this vulnerability?<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>It seems that it is not only on cisco CE500 only but on
all types of cisco switches.<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Thanks,<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Jeff<o:p></o:p></span></font></p>
</div>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'><o:p> </o:p></span></font></p>
<div>
<p class=MsoNormal><span class=gmailquote><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'>On 7/4/07, <b><span style='font-weight:bold'>Lee
Pedder</span></b> <<a href="mailto:lee.pedder@gmail.com" target="_blank">lee.pedder@gmail.com
</a>> wrote:</span></font></span> <o:p></o:p></p>
<div>
<blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt;
margin-left:4.8pt;margin-right:0in'>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>I can't offer specific advice on the CE500 switch, but on other cisco<br>
switches there is a bpduguard feature that you need to enable if you <br>
are using spanning-tree portfast. This will shutdown a port on receipt<br>
of a BPDU (such as one received from itself on another port).<br>
<br>
On 04/07/07, Jefflin Choi <<a href="mailto:jefflin.choi@gmail.com"
target="_blank"> jefflin.choi@gmail.com </a>> wrote:<br>
> Ahmed,<br>
><br>
> The users are using PC connected to the IP phones. Someone non-technical<br>
> plugged both connections to the switch instead of one cable to the PC. <br>
><br>
> Educating end users to plug the ip phones to the correct devices is simple
<br>
> but this is a security risk which can cause sabotage of the network.<br>
><br>
> Matt,<br>
><br>
> I do not see how "Try turning off GARP on the phone, disable web
access and <br>
> turn off voice vlan access." can help. Can you explain why this will
help <br>
> solve the problem.<br>
><br>
> First, web access can be disabled. No problem with it. I can't see the<br>
> relation with the loop though. <br>
><br>
> second voice vlan access, you mean to say not to allow the voice vlan on
the <br>
> trunk?<br>
><br>
> Thanks,<br>
> Jeff<br>
><br>
><br>
><br>
><br>
> On 7/4/07, Ahmed Elnagar <<a href="mailto:aelnagar@act-eg.com"
target="_blank"> aelnagar@act-eg.com</a>> wrote:<br>
> ><br>
> ><br>
> ><br>
> > Well, I was not trying to answer the Q. I was just sharing my
dislikeness<br>
> of this switch as I had alot o problems with it :), sepically with vlans <br>
> trunking. I had it running with IP Phones normally with no problem. <br>
> changeing the port role on the switch sometimes it helps, but I dont think<br>
> in <st1:City w:st="on"><st1:place w:st="on">ur</st1:place></st1:City>
case. but what I got from <st1:City w:st="on"><st1:place w:st="on">ur</st1:place></st1:City>
words seems that the users is not using a <br>
> PC connected to th phone (otherwise they will connect 2 cables from the <br>
> switch) if that is the case try to disable the PC port of the IP Phone.<br>
> ><br>
> ><br>
> ><br>
> > Thanks and Best Regards <br>
> ><br>
> > Ahmed A. Elnagar<br>
> > Network Engineer Specialist <br>
> ><br>
> > Advanced Computer Technology (ACT)<br>
> > 16 Fawzy Ramah St.Off Shehab St.Mohandessin, <st1:place w:st="on"><st1:City
w:st="on">Giza</st1:City>, <st1:country-region w:st="on">Egypt</st1:country-region></st1:place><br>
> > Postal Code:12411 <st1:City w:st="on">Cairo</st1:City> <st1:country-region
w:st="on"><st1:place w:st="on">Egypt</st1:place></st1:country-region> <br>
> ><br>
> > Mob : +2010-2833868<br>
> > Website: <a href="http://www.act-eg.com/" target="_blank">www.act-eg.com</a><br>
> > E-mail: <a href="mailto:aelnagar@act-eg.com" target="_blank">aelnagar@act-eg.com</a><br>
> ><br>
> > ________________________________<br>
> From: <a href="mailto:cisco-voip-bounces@puck.nether.net"
target="_blank">cisco-voip-bounces@puck.nether.net</a> on behalf of Matt<br>
> Slaga (US)<br>
> > Sent: Tue 03-Jul-07 3:25 PM<br>
> > To: Ahmed Elnagar; Jefflin Choi; <a
href="mailto:cisco-voip@puck.nether.net" target="_blank">cisco-voip@puck.nether.net</a><br>
> > Subject: Re: [cisco-voip] cisco IP Phone causes stp loop.<br>
> ><br>
> ><br>
> ><br>
> ><br>
> ><br>
> > Wow, that reply should help you solve that problem lickety split! <br>
> ><br>
> ><br>
> ><br>
> > Try turning off GARP on the phone, disable web access and turn off
voice<br>
> vlan access.<br>
> ><br>
> ><br>
> ><br>
> ><br>
> ><br>
> > <br>
> ><br>
> ><br>
> ><br>
> > From: <a href="mailto:cisco-voip-bounces@puck.nether.net"
target="_blank">cisco-voip-bounces@puck.nether.net</a><br>
> [mailto:<a href="mailto:cisco-voip-bounces@puck.nether.net" target="_blank">cisco-voip-bounces@puck.nether.net
</a>] On Behalf Of<br>
> Ahmed Elnagar<br>
> > Sent: Tuesday, July 03, 2007 3:25 AM <br>
> > To: Jefflin Choi; <a href="mailto:cisco-voip@puck.nether.net"
target="_blank">cisco-voip@puck.nether.net</a><br>
> > Subject: Re: [cisco-voip] cisco IP Phone causes stp loop. <br>
> ><br>
> ><br>
> ><br>
> > Just a note<br>
> ><br>
> > I Hate 500 Express it is a very bad switch and it has a lot of
strange<br>
> configuration setting plus no useful troubleshooting capabilities at all. <br>
> ><br>
> ><br>
> ><br>
> > ________________________________<br>
><br>
> ><br>
> > From: <a href="mailto:cisco-voip-bounces@puck.nether.net"
target="_blank">cisco-voip-bounces@puck.nether.net</a><br>
> [mailto: <a href="mailto:cisco-voip-bounces@puck.nether.net"
target="_blank">cisco-voip-bounces@puck.nether.net</a>] On Behalf Of <br>
> Jefflin Choi<br>
> > Sent: Tuesday, July 03, 2007 9:56 AM<br>
> > To: <a href="mailto:cisco-voip@puck.nether.net" target="_blank">cisco-voip@puck.nether.net
</a><br>
> > Subject: [cisco-voip] cisco IP Phone causes stp loop.<br>
> ><br>
> ><br>
> ><br>
> ><br>
> > Hi all,<br>
> ><br>
> ><br>
> ><br>
> > <br>
> ><br>
> > Some end user plugged the pc port and switch port of an IP Phone to a
<br>
> Catalyst CE500 port at the same time causing our client's switch on a
loop.<br>
> ><br>
> ><br>
> > <br>
> ><br>
> ><br>
> > CE500--------7912 IP Phone<br>
> ><br>
> ><br>
> >
| |<br>
> ><br>
> ><br>
> > |------------------------|<br>
> ><br>
> > <br>
> ><br>
> ><br>
> ><br>
> ><br>
> > We can't prevent end user making accidental mistakes like this which
might <br>
> cause network failure.<br>
> ><br>
> ><br>
> ><br>
> > <br>
> ><br>
> > I was wondering if Cisco IP phones are sending BPDU so that the CE500
will<br>
> errdisable the port. Doesn't it? <br>
> ><br>
> ><br>
> ><br>
> ><br>
> ><br>
> > Any way to prevent the this from happening? <br>
> ><br>
> ><br>
> ><br>
> ><br>
> ><br>
> > Thanks,<br>
> > <br>
> ><br>
> > Jeff<br>
> ><br>
> ><br>
> ><br>
> ><br>
> > ________________________________ <br>
><br>
> ><br>
> ><br>
> ><br>
> > Disclaimer: This e-mail communication and any attachments may contain
<br>
> confidential and privileged information and is for use by the designated<br>
> addressee(s) named above only. If you are not the intended addressee, you <br>
> are hereby notified that you have received this communication in error and
<br>
> that any use or reproduction of this email or its contents is strictly<br>
> prohibited and may be unlawful. If you have received this communication in
<br>
> error, please notify us immediately by replying to this message and
deleting <br>
> it from your computer. Thank you.<br>
> ><br>
> ><br>
> ><br>
> ><br>
><br>
><br>
> _______________________________________________ <br>
> cisco-voip mailing list<br>
> <a href="mailto:cisco-voip@puck.nether.net" target="_blank">cisco-voip@puck.nether.net</a><br>
> <a href="https://puck.nether.net/mailman/listinfo/cisco-voip"
target="_blank">https://puck.nether.net/mailman/listinfo/cisco-voip </a><br>
><br>
><br>
_______________________________________________<br>
cisco-voip mailing list<br>
<a href="mailto:cisco-voip@puck.nether.net" target="_blank">cisco-voip@puck.nether.net
</a><br>
<a href="https://puck.nether.net/mailman/listinfo/cisco-voip" target="_blank">https://puck.nether.net/mailman/listinfo/cisco-voip</a><o:p></o:p></span></font></p>
</blockquote>
</div>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><br>
<o:p></o:p></span></font></p>
</div>
</div>
</div>
</div>
</span>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
</div>
</body>
</html>